1. Dating a manipulative asshole.
Your friends tried to get you to break up with this person but you never did because you had to see it for yourself: some people are just shitty people who are so insecure that they're more in love with controlling another person than they are with you. No, you'll never get the time you spent with this person back, but that's OK because you will channel it into never letting another person treat you like shit ever again.
2. Taking a trip with friends that turned out to be a total disaster.
You see the truest of true sides of people when you travel with them. If you take a friend trip that turns into utter hell, you can rest in the solace of knowing that Chris is a two-hour-friend only and Becky is a grade A garbage person you don't need in your life.
3. Getting fired.
Whether this is because you actually do something wrong at work or because you were working at a lousy startup that was so disorganized they had no idea who they'd want on the team in six months and that person wasn't you. If you messed up you'll learn so much from it. And if you just worked for a garbage company you'll learn how to spot garbage employers in the future and not pursue jobs there.
4. Going on a diet to lose seven vanity pounds.
Once you're not on a diet and stop worrying about what you're eating, you realize your weight is just about the same whether or not you obsess over it, so why the hell are you obsessing over it?! Bring it on, ice cream when I feel like it.
5. Staying out past 2 a.m. every time you go out.
Nothing good happens after 2 a.m. even if the bars in your town are still open past 2 a.m. Think of it as the Seinfeld exit: everyone's having fun (including you!) and you're a little drunk but you don't want all this revelling to get tired and weird and you kind of do want to go to yoga tomorrow morning after all so you learn to leave on a high note. And that high note always strikes at 2 a.m.
6. Buying a bunch of weird designer clothes because they're on sale and you think designer things make you Cool.
Call this a lesson in fashion and money management: eventually you realize you can just buy things that aren't that weird and do fit you well at Zara and H&M and Forever 21 and labels are just labels! Don't let a tag sewn onto some fabric trick you into thinking one item is more worth your money than another with a different tack stuck to it. The best clothes aren't the best because they have a logo on it; the best clothes are the best because they make you feel amazing!
7. Wearing a totally weird trend that looks good on no one because you're determined to be trendy.
The photos will be PRICELESS sooner than you think. Your children will love twentysomething you forever.
8. Idly waiting for the perfect boyfriend to come along.
We've all seen romantic comedies and we all know they're full of lies. Meet cutes were probably invented by God exclusively for screenplays. Once you get tired of waiting for someone to pick up your breakfast pastry after you so cutely drop it on the floor of Starbucks only to write your number on a napkin before taking you on a date in his private helicopter Christian Grey-style, you'll start asking dudes out! Or saying yes to dudes you normally say no to and eventually you'll love one so soul-crushingly hard you'll realize that's how you really meet nice guys. You'll never be so close-minded again.
9. Trying hard to be cool.
Who gives a flying eff about being cool. Being cool takes energy and attitude and even more energy for your attitude! But once you've been cool and decide to take a break from it because you realize that it's exhausting and requires uncomfortable shoes, you'll realize it's so much better to just be who you are! And if who you are is a girl who loves Jonathan Franzen novels and going to bed by 11 every night, so be it!
10. Picking terrible roommates.
She doesn't pay the bills, she leaves pizza boxes on the rug, she very well might be a pathological liar. Well once you're done with her you will never let anyone into your home without a credit check again. Sometimes the only way to learn is the hard way.
11. Not actively trying to make friends.
You kind of have to join book clubs and stuff if you want to continue making friends in your twenties. They don't just fall into your lap—you have to find them and in order to find them you have to let yourself be found. Once you hibernate enough you realize this and join all the book clubs and life is great!
12. Trying to change someone.
People can only change because they decide to, not because you want them to. Failing at this is sometimes the only way to learn it. You can't control other people—the only person you can control is yourself so spend your energy worrying about YOU, girl!
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.