Never assume anything in your teens – they’re a magical time when anything is possible. Your twenties, on the other hand, can be pretty dang formative, especially when your prefrontal cortex develops and you start to make habits to last you a lifetime. It’s never too late to start over, but it’s also great to give yourself a head start.

1. Stop hanging out with people you don’t like. Start accepting your own company is sufficient.

Seriously, haven’t you better things to do on a Saturday night than put on a pretty face for a bunch of “friends” you hate? Why are you still parroting nonsense you don’t subscribe to in order to please this lot? You’re not in high school anymore, and hanging out with a bunch of assholes who wouldn’t piss on you if you were on fire is no longer necessary for your survival. In fact…

2. Stop dropping good people because they’re “not cool enough.” Start attracting the kind of friends who will look out for you.

Being cool is overrated, and easy. Being genuine, honest, and loyal? That takes guts, because it usually means spending copious amounts of time on your own. Fact: when you surround yourself with the vacant and the casually cruel, you’re driving away anybody who might actually be by your side when you need them.

3. Stop acting like “fairness” has anything to do with it and seek justice instead.

The older you get, the more often you will encounter situations that are wrong. You’ve got two choices – you can get hung up on how “fair” or “unfair” it all is, gnash your teeth and stomp your legs and demand that all be set right in this world without actually making an effort… or you can roll up your sleeves and set it right yourself. One choice means abdicating all responsibility and waiting passively. The other means taking charge and trying to make a difference. Which kind of person would you like to be in your 30s?

4. Stop settling—you deserve better.

See point 3 for more clarification. You think it’s only fair that the people in your life use and abuse you? You think you’re the kind of rotten person that does not deserve loyalty, kindness, or basic human decency? Life is not fair. Nobody else can make you believe in your own worthiness, and it will take you a hell of a long time if you keep putting yourself in a social circle that constantly undermines you. Do yourself a favor and find people who will speed up the process – your older self will thank you.

5. Stop destroying yourself with excesses and start listening to your body.

When does a good time turn into a bad one? Where does a person stop exercising their right to unwind and let off steam, and lose all control of themselves? It’s not an easy question to answer, but usually, your own body will start to tell you when something stops feeling good. I have no idea what your life is like, but a good rule of thumb is: when your body starts to tell you something is wrong, listen to it and stop doing the thing that’s destroying you.

6. Stop putting off necessary things.

Dental checks. Physical exams. Flu shots. Taxes. Nobody likes being told to do something, but the longer you make a habit of avoiding and putting off necessary aspects of life, the more difficult it is to start changing them later in life. If you make a big deal out of having your teeth cleaner, it’s going to be a big deal every time you get a reminder from your dentist. If you treat it like a quick item off a to-do list, it loses its power to terrify you, and you get it done faster.

7. Stop treating money as a big, confusing thing. Get to know it instead.

The sooner you educate yourself about money, the better. Price of living per geographic area, additional costs of travel and transport, size of debt, interest rates, what is realistic to pay off, what is not, when’s a time to look for a better job and when’s it more appropriate to keep at it and shoot for a promotion. Follow Amanda Steinberg’s advice, wake up from the money coma, and for the love of all that’s holy, don’t just let someone else manage your checking account.

8. Stop avoiding responsibility. Be the person who knows how to apologize.

You know what you did wrong. Learn to take responsibility, apologize, and make amends, so that you enter your 30s with confidence. You’re human – chances are you will fuck up in your lifetime – but knowing that you can do the right thing when you do gives you power that cowardice does not.

9. Stop taking the blame when it’s not yours to handle. You deserve to have some boundaries.

Recognizing what blame is yours and what isn’t takes practice. That doesn’t mean, however, that you should apologize for everything just in case it’s your fault. Yes, being able to say sorry is important; but so is knowing when someone is trying to make you feel bad about something you have no control over.

10. Stop waiting for people to change. Be the change you want to see.

Relying on someone else to suddenly morph into the kind of person you need – a friend, a parent, a lover – means to give them all control over your own happiness and well-being. It’ll be nice if this person suddenly realized what was missing from their life and making active changes to do better, but that drive can only come from them – you can only change yourself.

Realizing that – how little power you have over other people, how much you hold over yourself – does not make your life perfect but it does allow you to move through your years with more certainty. It helps you make decisions when to stay in someone’s life and when to walk away.

It keeps your mind healthy and your boundaries strong. It’s a good building block for happiness at any age.