If you want to start a startup, don't learn "entrepreneurship." Learn how to build things. The hard part of startups is not "entrepreneurship" but product: to know what to build, and to be able to build it.
You should study what makes you defensive. The topic you avoid, the joke that irritates you, the question that feels insulting, the feedback you instantly reject. Defensiveness is usually the guard dog sitting in front of a weakness you have not trained yourself to face.
Somewhere in your 20s or 30s you’ll get the opportunity to rebuild your life after a negative loop, heal from what broke you, live in your own space, reconnect with your discipline, and learn to love yourself again. It’s very important that you see that journey through.