30s are not the new 20s. Your 30s are when you start being “old”
People describe your 30s as like your 20s but with more money, but the truth is once you’re in your 30s a lot of the stuff you are able to/want to do in your 20s becomes much more difficult or at least less appealing.
-First, the personal decisions you’ve made up to this point start to catch up with you. In your 20s you usually can’t tell what kind of lifestyle someone leads just by their physical appearance (barring extremes, like obesity, addiction to hard drugs, being an athlete or extremely fit). In your 30s you start being able to tell.
-This is also true medically, not just appearance wise— someone with a poor diet in their 20s becoming overweight and pre diabetic in their 30s for example. You also just notice a subtle but real loss of physical resilience. You pull muscles a bit easier, the boundless energy of your youth starts wearing off.
-Socially your options also start to decline as many of your friends get married/have kids. You can’t just text your buddy at 6pm and ask if he wants to grab food at 8pm. If you are in a LTR and/or have kids most of your social life will also revolve around these things. I think the loss of that kind of spontaneity is one of the biggest things that is different about being in your 30s vs your 20s.
-If you thought dating in your 20s sucked, dating in your 30s is harder (especially if you are a woman who wants biological children). Your dating pool is reduced, and people who you do meet will be much less flexible and open to getting to know someone who doesn’t check all the boxes from day 1. In some ways this is good because you waste less time on people you’re fundamentally incompatible with, but it is also less fun, and dating can start feeling more like doing job interviews.
-And while you will probably have more money than you did in your 30s, your career has a high likelihood of being more demanding than it was in your 20s. Even if you don’t work more total hours, you probably have more responsibilities and have to deal with more shit than you did early in your career and that is exhausting.
I believe that your 30s are the start of getting old because these things (decline in health/appearance, social and dating options, personal spontaneity) are markers of aging that start gradually but noticeably in your 30s but continue to get worse as you age into your 40s, 50s, etc.
Your 30s CAN BE awesome and fun and fulfilling. You’re not a prune yet, you won’t need a hip replacement, and some things actually ARE better in your 30s than in your 20s. You’ll probably have more money and a better sense of who you are and what you want out of life and you can pursue those things in a more intentional way. But you are gonna start experiencing what aging means on multiple levels and it’s ok to acknowledge that.