This'll probably get lost b/c I'm posting it 6 pages in...
I'm gonna be 31 soon. I'm far from an old wise sage, but I think I've being in your 30s can somewhat qualify you to give some good advice. Here's what I learned:
- Value your Youth - Your 20s last a few seconds - They are slow at first and begin to speed up. One day you are young and the prime audience of pop culture. Before you know it, pop culture is catering to a younger crowd. The music sounds stupid. The lingo is dumb. Like someone said it doesn't matter how "cool" you were in your hayday, everyone your age and above is the same age "lame". Soon there will be people much younger than you and much older, but no one your age for some reason.
Major in STEM - If you go to college and not trade school, don't major in any other crap or you won't be able to find a job. You can major is some other fields if you plan to go to graduate school.
Stop giving a fuck what others think - A good 90 something percent of people are only going to be in your life for a short period of time. Don't waste time worrying about what they think of you or living your life trying to please them. Even your parents; so many people are living their parents' 2nd life, and it's really a waste.
Don't get a record- You'll realize how stupid little fights are and how childish "posturing" is when you get older. "I gotta fight him because he called me a bitch" in hindsight is the dumbest thing ever. Don't do other stupid crap, that'll get you in trouble. Your feelings are temporary, a record is forever.
Learn, travel, meet other people - The number of people who never leave their circles is ridiculous. In your youth you are freer than you will ever be. Hang out with a different crowd. Learn a new culture, grow the fuck up! It'll give you more stories, make you more interesting, and you'll be more cultured.
On women:
Have sex with a lot of women - Not irresponsibly so that you get an STD, pregnancy, or MeToo'd. At a certain age that's all they want to do, later the get a bit more conservative. Get it out of your system. What you haven't gotten out of your system is going to be unfinished business that want's to creep up later.
After your 20s - You're gonna feel creepy talking to girls who are 18 to early 20s when you are in your 30s.
Approach the hottest girl - Seriously, if you see Gal Gadot at a party and she's single go talk to her! There is no magic line, just start chatting and see where it goes.
There are almost 8 billion people on the planet. No one gives a fuck if some girl rejected you, it isn't as important as you think it is. Not every hot girl is a bitch, and not every homely girl is easy. You won't believe the opportunities you missed out on because you were too scared to act and (falsely) thought you'd get rejected. If you do get rejected they'll be another hot one.
There is no perfect woman - Everyone has flaws and ALL chicks are at least a little crazy. When you find the right one, don't sabotage it and regret it later, hold on to that crap. The grass isn't greener on the other side.
Don't get married too fast - Listen to me, you're an idiot... you can't see it while you're young, but you'll realize it when you get older. You don't know what you want. Hell, "what you want" is gonna change many times. Yes, we all know some high school sweethearts who got married and remained married for 2,343 years and lived happily ever after, but there are a lot of young bf and gf who got married too fast because of puppy love and it ended up miserable. If you guys are meant to be together it'll happen, stop rushing it because you see all of your friends on Facebook doing it!