Today is my birthday. This is Thing Thirty, and it's the most important one.
In reality, it's just a generalization of all the other Things that I've enumerated: eat new things, learn new languages, go new places. Create. Learn. Push.
And that's Thing Thirty: to just keep pushing. Keep trying. Don't get complacent, don't get in a rut. Try new things. That's how to stay young.