1. Not getting enough sleep.
"But Anna," you ask, "How can I sleep when there are so many mistakes to make?!" Don't worry, you have an entire decade's worth of days and evenings to irrevocably fuck up your life. (1.5. Not washing the pillowcases often enough. Once a week, or else your skin will suffer.)
2. Being addicted to social media.
He liked that picture of your cat on Facebook, and then you retweeted his tweet, and then you trolled all of his friends' Instagrams to try to find out if he was dating someone else, and then he posted a news article to your wall that related to this inside joke you guys have, and by the way, it is a beautiful day outside.
3. Washing your hair too much.
Yes, too much, especially if it's not stick-straight! By the time I was 24 my hair had the consistency of tree bark. Skip a few shampoos and just condition, or use dry shampoo!
4. Wasting money on restaurant meals.
Just think of how much money you could've saved if you didn't insist on having weekend brunches at overpriced ~*artisinal*~ brunch places at the Fort with your girls.
5. Being health-bipolar.
During the day we're drinking green juice and going to yoga. At night we're out partying with friends and ending the night with 4 a.m. fast food. The former does not detract from the latter—your body is just confused as shit. :(
6. Trying to tan.
Ack! Stop. UV rays are no good.
7. Spending all your time in a relationship.
Friends of mine who were with the same guy all through their twenties are lamenting it now. To truly appreciate the good men, you have to road test the bad ones.
8. Or chasing after someone who is completely disinterested in you.
Does he never ask you questions about yourself? Swoon. Does he take at least 24 hours to text you back? Nice. Are you in his phone as "Mike" so that the other girls he's hooking up with don't know? Yayyy! (No.)
9. Getting sloppy with birth control.
It is a joke to try to pretend that it doesn't feel better without a condom, but everyone's gotta. You gottttttta.
10. Get a long-term pet with a significant other.
So you and your boyfriend decided to drop a few of your start-up paychecks on Rambo the Chow Chow. If you don't last as a couple, Rambo is a child of divorce, which we all know is a gateway to drugs and juvenile delinquency.
11. Drunk texting/dialing.
And rolling over in the morning dreading to look at your phone. Hoooo boy do I know what that's like.
12. Extreme diets.
No matter how many lemon juice, cayenne pepper and holy water holistic cleanses you go on, you'll end up at your normal weight ultimately.
13. Hoard trend pieces instead of saving for something expensive and timeless.
A cheapo peplum top (last year) or pleather leggings (2007)ish are always bound to go out of style, like, tomorrow.
14. Splurging on beauty products that you know in your heart you won't use.
Because you know, you really need a million red lipsticks and about a thousand black eyeliners.
15. Spending a lot of energy on envying someone you have decided is your nemesis.
She is the 2.0 version of you, in possession of the career, boyfriend, wardrobe and apartment of your dreams. Or she is just an acquaintance whose superiority complex and complete lack of self-awareness annoyed the shit out of you. (Not that I'm writing this from experience or anything.) Take a breath, and let it go.
16. Letting harsh judgments of your friends' boyfriends' (or your friends' harsh judgments of your boyfriend) tear apart close friendships.
He's a tool. Just let everyone figure it out on their own time.
17. Letting your office treat you like an intern when you haven't interned in years.
Yes, your mom's over-enthusiastic friends are right when they tell you "how lucky you are to have a job in this economy." But being a full-fledged employee with a salary who is regularly told to get coffee for supervisors and carry heavy boxes is bullshit.
18. Hooking up (the "feelings" way, not just the "casual" way) with a friend's sibling.
If the sibling lives in the same town that you both do, this is the most awkward social decision you can possibly make. Just don't do it.
19. Pick the wrong-ass roommates.
Sure, she was a good nightlife friend in college. That's about it.
20. Slow down.
Adulthood doesn't happen overnight. Enjoy the decade—appreciate your wide-open future and perky boobs while you still can.
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.