does homework help you learn?

Homework is actually for review. Not learning anything new.

Indeed. For instance, doing physics-homework is something I do even without my teacher asking nowadays. You may question why, and it's as simple as this:
I'll remember stuff better (review, repetition, keep it fresh to be able to remember it better, you see the idea) and I'll be able to solve all kinds of exercises easier and faster. It basically helps me to "think" more as a physician and develop ways that I will bring into work someday.