I'm turning 40 next month and i've been around imageboards since 2007 and I used to see threads just like that.
The only advice you need to internalize is that life goes by fast and that you should take every oportunity it throws at you.

Go ask out that girl you like;
Try that new job you want to pivot your career into;
Start that new hobby you always wanted to;
Maybe quit your job;
Go on a long trip by yourself;
Say how much you love your parents;
Don't let time slip through your fingers and bury you in regret.