1. Don't be afraid to change up your look.
2. Create learning opportunities for yourself.
3. It's OK to admit when you're wrong.
4. Get politically active — your voice matters!
5. You need people in your life who will tell you when you're being an idiot.
6. Focus on what you love about your body, not what you'd like to change.
7. Time spent on Tumblr is not wasted.
8. Put down your phone every now and then.
9. There is no "right" time to start a family.
10. Take pride in your accomplishments!
"Ladies, there is a difference between being humble and working hard to see the fruits of your labor blossom, and your dreams realized,” Katy wrote in an Instagram essay earlier this year. "It's okay to be proud of hard earned success and that there is no shame in being a boss."
11. Experiment with hobbies until you find one you truly love.
12. Public transit is as glamorous as you make it.
13. Developing your selfie game takes time.
And lots of practice!
14. If somebody comes for you and yours, don't be afraid to stand up for yourself.
15. Nobody really wakes up looking **flawless — not even famously glam pop stars.
16. Sharing the spotlight doesn't dilute your shine.
17. Seriously, success is more fun when you have people to experience it with.
"I love [Rihanna] and every time I see her, I'm reminded of the light that she has," Katy said of her famous BFF during an interview with Elle UK back in 2013. "There's a lot of dark in this business."
18. Be considerate of other people's feelings.
19. But don't expect brownie points every time you do something nice for someone else.
20. Expand your palate as you expand your horizons.
21. Your tastes and interests are going to evolve over time.
22. Find ways to embrace your flaws.
23. Learning what you want and need in a relationship is going to take some trial and error.
24. Fashion should be fun.
25. Wanting to win is not the same thing as wanting other people to lose.
26. Embrace the idea of "fake it til you make it."
Sometimes the only way to get out of a funk is to pretend you were never in one in the first place.