Doctors go through lectures and have practical training. Some doctors go on to treat people, others go on to research medicine further and develop better practices, new procedures, and better ways of doing things.
When I'm playing video games, I will do research on what others thing the best build for my class is, I'll run my own spreadsheets, and I'll test things out, before applying them.
I think the same applies to martial arts. You listen to your master or instructor, you ask questions, you play around with things to see what works best. Other times you drill to hit stuff, or to keep from being hit by stuff.