r/YouShouldKnow

I always figured private browsing plus a VPN made me more or less anonymous online. Not invisible, but close enough that no random website could pick me out of a crowd. Last week I got curious enough to actually test that assumption, and the short version is: it barely mattered.

I ran my browser through a handful of tracking checks covering stuff I never thought about: canvas and WebGL fingerprinting, which reads tiny rendering quirks unique to your GPU, the audio signature my hardware produces, whether WebRTC was leaking my real IP, which DNS resolver I was using, and a baseline fingerprint from my screen size and timezone. Also my full installed font list. 312 fonts, and that set alone was nearly enough to single me out.

Normal window first. Uniqueness score: 1 in 294,000. Then incognito, VPN on, ran everything again. 1 in 286,000. Incognito wiped my cookies and local storage, which is all it really changes about how the page sees you, but every hardware fingerprint came back identical. The VPN masked my exit IP, but WebRTC handed my real local address to the page anyway because I hadn't toggled the browser setting to block it. The canvas hash was the one that actually stopped me scrolling. Exact same string both runs, character for character. Incognito does not touch your GPU output.

I still use private browsing. It keeps your history off a shared laptop and that is genuinely what it was built for. It just was never meant to stop a site from recognizing your browser across visits, and I spent years assuming it handled both.

Why YSK: most people (well, me until eight days ago) don't realize that fingerprints let ad networks and data brokers stitch your activity across completely unrelated sites into one profile, no cookies needed. That profile survives clearing your data, switching to incognito, and changing your IP, because none of those alter what your hardware looks like to a webpage. Knowing which surfaces are actually exposed is the first step to deciding whether that tradeoff is worth acting on.

Why YSK: Because treating a temporary soft moment as a fun break instead of a problem makes the sex infinitely better for both of you.

Bodies are weird and sometimes a random noise or pausing to put on a condom makes you lose your rhythm. It is totally fine and happens to everyone.

Instead of stressing out, just lean into it. Tell your partner they look incredible and you just want to feel their body and make out for a minute. Taking the pressure off and just enjoying the skin contact is incredibly hot and shows real confidence.

It turns a simple pause into pure intimacy, and the erection always comes back on its own when you are just having fun.

Why YSK: Understanding this chemistry stops you from ruining a perfectly good cup of coffee if you try to make it or order it, and clears up the common myth that the no-stirring rule is just about keeping the foam intact.

A popular post recently claimed you don't stir sugar into Turkish coffee because it physically breaks the foam. While the foam part is visually true, the real reason goes back to basic coffee chemistry.

Turkish coffee is ground much finer than espresso, almost like dust. When you brew it, you put the water, coffee, and sugar in all at once. As the sugar dissolves, it actually thickens the water slightly. This denser water slows down how fast the coffee extracts, acting like a buffer so this ultra-fine coffee doesn't get insanely bitter while slowly heating up on the stove.

If you wait until it's brewed and then dump sugar in and stir it, you cause massive agitation right at the peak temperature. That sudden stirring forces the coffee grounds to release all their harsh tannins instantly, ruining the taste. Plus, you stir up the mud at the bottom.

So you pick your sugar level before brewing because the sugar is literally part of the chemical brewing process, not just a sweetener you add at the end.

Why YSK: people online love to correct something that’s wrong on the internet, so if you post an incorrect fact you’ll find out the truth fast and easy.

I went down a massive rabbit hole researching screen time because the tantrums in my house were getting out of control. It turns out that endless scrolling and fast-paced videos flood the brain with cheap dopamine. It requires zero effort to get a massive chemical reward. When you take the device away the brain crashes and the kid literally experiences withdrawal. That is why they scream. They are not just being brats. Their brains are panicking. I had to completely overhaul how we handle digital devices and dopamine in my house and it was a nightmare but it saved my sanity. If your kid cannot sit still in a restaurant without a tablet or phone you need to start a detox right now before it gets worse.

Why YSK: Parents usually think their kids are just misbehaving or going through a phase when they throw tantrums over devices. Understanding that this is an actual chemical withdrawal in their brain helps you stop blaming yourself and start fixing the real problem before their attention span is ruined forever.

Why YSK: Smoking makes arteries less stretchy and therefore more prone to breaking. Your aorta is an artery that supplies the whole body with blood. If it ruptures, even if you're actively in the operating room to get it fixed, your chances of survival drop to almost 0 immediately. Any type of surgery becomes higher risk because smoking makes tissue very friable (fragile, thin, tearable). That means more bleeding and risk of complications

Source: https://www.nature.com/articles/s41598-025-18013-x

Why YSK: After seasons of use, 20 inch box fans get built up dirt on the blades. Sometimes the blades need to removed for the best cleaning or even repair of cracks. I just used a new method for getting the blade off. Rather than trying to pull it off of the motor shaft, I removed the grilles and blocked up just two sides of the metal frame clear of the blade edges and used some smaller blocks to _push_down on the plastic fan blade center. This is much safer than a technique shown on youtube by standing on the frame on the floor and trying to get leverage.

Why YSK:

Grocery stores aren’t just selling you milk and eggs these days, they’re selling your data too. Every time you punch in your phone number, scan a loyalty card, or open a grocery app for a “digital-only” price, the store learns a little more about you. What you buy. When you buy it. How much you’re willing to pay. And in a lot of cases, that information doesn’t just sit there. It gets analyzed, used to target you, and sometimes shared with partners.

Here's what's really happening and how you can limit the personal information you give out and still score deals.

What’s actually being tracked

The store can track the following when you use a loyalty card or app:

Your identity (name, email, phone)

Your purchase history (every item, size, brand, and price)

Your visit patterns (Sundays at 10am, every 6–8 days, big trip before holidays)

Your coupons and offers (which ones made you buy and which ones you ignored)

Your device/app behavior (you opened the app near the store, clicked on the weekly ad, loaded offers, etc.)

Put all of this together and they start to get a pretty clear picture of your household and spending habits. For example, if you always buy gluten-free, they know it. If you switched from a national-brand cereal to a store-brand, they know you’re price-sensitive. If you only buy baby products once a month, they can guess what stage you’re at raising your family.

Why YSK: Spotting payment packing can save thousands of dollars if financing a car at a dealership.

What is payment packing?

Say you go into a dealership to buy a car and decide to finance a car for 40K for a 60 month term. The finance guy comes back and offers a loan at 6%. The actual monthly payment for this loan is ~$774.

The people at the dealership however might deliberately lie and quote a higher monthly (say $825) than the actual $774 number. It's hard to spot this inflation since calculating monthly payments is not easy mental math.

They then pitch you add ons like extended warranty and added protection at a slightly higher number than $825 (like $850). The value proposition seems feasible since it seems like just $25 extra on the monthly. However in reality it's an extra $76 per month from the actual $774 number. Which comes out to ~$4500 over the full term of the loan.

How to spot payment packing?

Always use an online auto loan calculator to verify the monthly payments quoted by a dealer.

During intense physical intimacy your brain floods your system with dopamine and oxytocin. Once it ends those hormone levels drop off a cliff. This sudden chemical crash can cause a temporary feeling of emptiness anxiety or the urge to pull away even if the experience was great. It is a purely biological reaction but it ruins many encounters because the other person takes the sudden coldness personally.

Why YSK:
Understanding this chemical crash prevents you from feeling rejected when a partner suddenly needs space or acts distant after sex. It also explains why taking a few minutes to just hold each other and talk helps the brain transition back to normal without the emotional whiplash.

Have you ever tripped in public, stumbled over your words during a presentation, or worn something embarrassing and felt like everyone would remember it forever?

Psychologists call this the Spotlight Effect. We tend to overestimate how much other people notice and remember our appearance, behavior, and mistakes. In reality, most people are focused on their own lives and concerns, so the awkward moment you've have been replaying in your head is often forgotten much sooner than you think.

Why YSK: Knowing about the Spotlight Effect can help reduce unnecessary stress in situations like interviews, presentations, meeting new people, or simply making a small mistake in public. It doesn't mean nobody notices it just means they're usually paying much less attention than you imagine.

Source: Gilovich et al. (2000)

https://doi.org/10.1037/0022-3514.78.2.211

Why YSK: Canvas acts as a continuous data logger for your instructors. Your professors aren't just grading your final submissions; they have access to a backend analytics dashboard that tracks your exact login times, page clicks, file downloads, and video-watching heatmaps. Understanding what they can (and cannot) see can protect you from false cheating accusations and help you navigate grade appeals.

Canvas tracks user interactions as "Page Views" and "Participations" via a continuous activity log.

• Total Time Spent: A running clock of exactly how many hours, minutes, and seconds you have been logged into that specific course page.
• Page Views: A literal list of every single page, assignment, module, file, or quiz link you clicked on, along with the exact date and timestamp of when you opened it.
• Access Frequency: How many times you clicked on a specific item (e.g., if you opened the syllabus 14 times, they can see that count).
• Participation Flags: A log of specific actions, such as submitting an assignment, posting in a discussion board, or taking a quiz.
• Device/Login Data: The exact date, time, and general status of your successful logins to the platform.If a professor uploads a lecture video directly through Canvas's native media tools rather than just linking out to YouTube, they get an incredibly detailed Insights Dashboard.
  • Viewer Identity: A list of the specific names of students who clicked play.
  • The "Heatmap": A second-by-second graphical timeline for each student showing:
  • Exactly which parts of the video you watched.
  • Which sections you skipped over entirely.
  • Which sections you rewound and rewatched multiple times.
  • Completion Percentage: A precise metric showing how much of the video you actually completed (e.g., "Watched 42%").

When you take a quiz or exam natively inside Canvas, the platform generates a detailed Quiz Log that maps out your exact behavior during the test.

• Action Timestamps: The exact second you started the quiz, when you answered each question, and when you submitted it.
• The "Stopped Viewing" Flag: If you navigate away from the Canvas quiz page (even if it's just to look at a Canvas page in another tab, open a PDF your professor uploaded, or click outside the quiz window), Canvas logs an automatic event: "Stopped viewing the quiz canvas page."
• The "Resumed" Flag: It logs the exact second you click back into the test window ("Resumed viewing the quiz canvas page").
• Answer Shifts: If you change an answer, it logs the time of the change, allowing professors to see if a student spent 5 minutes on a question or changed it immediately after a "stopped viewing" flag.

File Downloads:

• Resource Tracking: If a professor uploads a PDF, PowerPoint, or Word Doc directly to the files section, Canvas tracks whether or not you actually clicked the download link or previewed the file, and when.

Professors rarely spy on this metadata daily just for fun. However, they routinely check it in two specific situations:

1. Academic Dishonesty Investigations: If an exam score looks suspicious or a student is flagged for cheating, the professor will pull the Quiz Log to look for matching "stopped viewing" patterns.
2. Grade Appeals & Extension Requests: If a student asks for a borderline grade bump, an extension, or claims they "didn't know about an assignment," the professor will check the Page Views log. If it shows the student hasn't logged into Canvas in two weeks, the request is usually denied.

Why YSK: If you are moving away from a location and do not want people to have your new forwarding address for safety purposes, this automated feature can reveal your new address. This comes into play when you have set up mail forwarding with the post office and your forwarding order expires. The post office will put a sticker on the envelope with "forwarding time expired, return to sender" and that sticker contains your last known forwarding address. I just sent out a huge batch of mail for work and saw this happen for over 100 recipients.

When you wake up from a nightmare or feel a panic attack coming on your body goes into fight or flight. You can try breathing exercises but sometimes they barely work. Then a pet climbs on your chest to purr or a partner just sits next to you breathing slowly and your panic melts away. This is a psychological and biological mechanism called co-regulation. Your dysregulated nervous system literally syncs up with their calm one to find its way back to normal.

Why YSK: We are constantly told we need to learn how to self-soothe and handle our dark moments alone. Understanding co-regulation proves that seeking out a safe animal or human when you are terrified is a hardwired biological hack to reset your brain. You do not have to fight your way out of the dark by yourself.

Alcohol is ALSO a Group 1 carcinogen (Hydes et al., 2019). It breaks down into acetaldehyde, which mutates cell DNA. Once ethanol enters the bloodstream, the liver metabolizes it into acetaldehyde a highly toxic chemical that acts like a physical blade inside your body, slicing through DNA strands and permanently binding to proteins. This direct cellular damage actively blocks cells from repairing themselves, leaving the body wide open to malignant mutations. The World Health Organization (WHO) and the International Agency for Research on Cancer (IARC, 2012) have found conclusive proof that this precise chemical process is directly responsible for triggering at least seven different types of cancer, including breast, liver, and bowel cancers.
In fact, medical and economic research published in The Lancet\\\\\\\*\\\\\\\* ranks alcohol as the number one most dangerous drug overall ranking higher than every substance yes even higher than LITERAL HEROIN !! This is due to the unmatched destruction it causes to both the user and wider society (Nutt et al., 2010).
But because roughly 80% of adults drink alcohol , it’s a protected cultural norm \\\\\\\*\\\\\\\*(NHS England, 2024). If people admit alcohol ruins lives, drains public funds, and causes cancer, they have to confront their own habits. It’s just much easier for people to demonise smoking because far fewer people do it now, making smokers an easy target for moral outrage.
Why ysk this because we cannot solve public health crises or reduce the immense financial strain on our healthcare systems if our laws and social morals are based on corporate marketing rather than objective medical science. Treating smoking as an unforgivable vice while protecting alcohol as a harmless cultural norm is a massive blind spot. Recognizing that alcohol is a Group 1 carcinogen and the overall most dangerous societal drug forces us to confront our own habits and demands consistency in how we address addiction, health, and public accountability.

References (since I know people will ask):

Hydes, T. J., Burton, R., Inskip, H., Bellis, M. A., & Sheron, N. (2019). A comparison of gender-linked population cancer risks between alcohol and tobacco: How many cigarettes are there in a bottle of wine? BMC Public Health, 19(1), Article 316. doi.org

International Agency for Research on Cancer. (2012). Personal habits and indoor combustions: A review of human carcinogens (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 100E). World Health Organization. nih.gov

NHS England. (2024). Health Survey for England 2022: Adults' health-related behaviours. National Service. digital.nhs.uk

Nutt, D. J., King, L. A., & Phillips, L. D. (2010). Drug harms in the UK: A multicriteria decision analysis. The Lancet, 376(9752), 1558–1 doi.org