Think you're a grown adult? Prove it, by not doing these 30 things.

1. Confusing there, their, and they’re.

It’s not that difficult.

2. Using text speech in emails.

No, I will not resched our mtg, k, thnx, plz.

3. Being rude to people in the service industry.

Yes, they’re being paid to pour your drink. No, that does not give you a right to treat them like dirt.

4. Complaining to people about things they cannot control.

Chances are, the person working at the store didn’t make up the rules of the store. Complaining to them isn’t going to do you or them any good. And it’s going to make you look like an asshole instead of the adult you are.

5. Hitting on people who have to be where they are.

Your waitress is doing her job. Stop hitting on her. That girl is trying to work out – that’s why she’s at the gym. Stop hitting on her.

6. Catcalling.

Yes, that person is attractive. No, they don’t need a complete stranger to tell them.

7. Talking loudly in a public place that’s meant to be quiet.

No one else is interested in you and your friends’ gossip, so keep it down. No, you do not need to be on your phone on public transport.

8. Interrupting.

Let the person finish their thought. Remember how we learned to wait our turn in preschool? Do the same as an adult.

9. Talking without listening.

What do you gain from a conversation if you’re only thinking about what interesting thing you have to say? Be an adult, and listen.

10. Paying more attention to your phone than other people.

You know that real-life experiences and conversations beat whatever is on your phone. Put it away.

11. Texting and driving.

Come on. You are way too old for that.

12. Ghosting.

Communicate your lack of interest. You’ll avoid hurting someone’s feelings, and they’ll leave you alone. It’s a win-win, really.

13. Posting petty shit on Facebook. AKA, Vague-booking.

No matter how veiled you think your status or meme is, we know that you’re complaining about someone specific – and sending them a message via passive aggressive Facebook post is beyond childish.

14. Oversharing online.

There are some parts of your life you should keep to yourself. For example, do not go ga-ga on your boyfriend on Facebook or post photos of the two of you in bed ... keep that stuff where it belongs: in the privacy of your own home.

15. Snapchatting your entire life.

How do you have that much time? And why are you wasting it? No one cares!

16. Posting embarrassing photos of other people – without their permission.

Do unto others…

17. Needlessly name-dropping.

Showing off that you know famous people just shows off that you’re insecure about your own lack of fame. And knowing a famous person doesn’t make you any cooler or more interesting!

18. Worshipping celebrities.

Why… do you care?

19. Fishing for compliments.

We know you’re insecure. And we know what you’re asking us to say. Please stop it.

20. Complaining about how much money you make.

When you make money. Be thankful you have a job. If you’re not thankful, go volunteer to help people who don’t have jobs. Get some perspective.

21. Saying things just to show off how smart you are.

If what you’re about to say has no importance other than to show off your big, fat brain, don’t say it. We get that you read. But you’re being pretentious and annoying.

22. Blaming other people for your problems.

Take a little responsibility. Reflect on yourself, your decisions, and your mistakes – rather than casting blame elsewhere and everywhere.

23. Talking shit about your friends, family, coworkers, or exes.

You’re an adult. If they’re that bad, go find other people, fix the relationship, or keep it to yourself.

24. Holding grudges.

Grudges are child’s play. Adults know that the best way to deal with conflict is to move on from it.

25. Prioritizing yourself over other people, all the time.

Sometimes you need to put yourself first. Fine. But most of the time, the opposite is true. You are a part of a human community, and you are not the center of it.

26. Littering.

It is not that difficult to find a trash can, and the world is not your dumpster.

27. Thinking your answers are everyone else’s answers.

What makes you happy and what makes your world go round isn’t the same for everyone else. Consider where other people are coming from, and that their answers and solutions may be totally different from your own.

28. Getting in dramatic fights ... in public.

Arguments happen. Sometimes, people even yell at each other. But don't get the public involved in your private affairs.

29. Eating junk food like it's a meal.

You should be treating your body better than that by now.

30. Treating people like they're nothing.

A person is a person, and every person deserves respect. Now go be an adult.