Work hard at math. One of the best skills you can learn at a young age is mental stamina. You have to be willing and able to keep working on hard problems long after they've become frustrating.

I didn't learn this until I was way too old, so please take some value from my advice. Keep working on the problems that challenge you.

Only if there's a financial incentive, which is questionable.

Living in a big city, the Milky Way is just a scientific fact. Out in the middle of darkest nowhere, it's something truly amazing.

I was on a beach in Hawaii one night and the sky was completely clear in every direction. It was the only time I ever really felt the truth of living on a rock in space. It felt obvious.

I imagine that feeling might have been more common a long time ago

I think you will find that the new testament has a book called Epistle to the Hebrews which is frequently shortened to just Hebrews.

Universal gravitation.

Newton's laws of motion, of course.

The rocket equation.

The escape velocity formula.