People who stand directly behind you in line and breathe on your neck
I don't know when this became acceptable but it happens to me at least once a week and every single time I have the same internal crisis about whether to step forward or just stand there and slowly lose my mind. You're at the checkout, or at the pharmacy, or waiting to order coffee, and there is a perfectly normal amount of space between you and the person in front of you. You're not sprawled out, you're not taking up extra room, you're just standing like a regular human being. And then someone gets in line behind you and positions themselves approximately four inches from your back.
They're not doing anything aggressive. They're not sighing loudly or nudging you. They're just. there. Right there. I can feel the air movement when they shift their weight. I can hear them breathing. One time I could smell whatever they had for lunch and it wasn't unpleasant exactly but I also did not consent to knowing that information about a stranger. The worst part is if you step forward to reclaim your personal space, they just close the gap again within like 20 seconds becuase they're not even aware they're doing it. It's not malicious. It's somehow worse that it's not malicious.
I've started doing this thing where I turn around to "check something in my bag" just to make eye contact and hopefully trigger some spatial awareness in them. It works maybe 40% of the time. The other 60% they just look at me and then go back to standing exactly where they were standing. I had one woman last week who was so close that when I turned around we were basically face to face and she didn't even flinch, she just looked at me pleasantly and said "oh sorry are you done?" I was not done. The line had not moved. She thought I was turning around to let her go first becuase she had apparently constructed an entire reality where she was not standing inside my personal space.
There is no line moving faster because you're closer to the person in front of you. The queue does not accelerate based on proximity. Standing two feet back instead of four inches back will get you to the register in the exact same amount of time and one of us will not spend that time calculating whether it's socially acceptable to say something to a stranger about their breathing.