I completely agree on that - it's exactly like math, the only way to truly learn it is to practice, over and over again, until you've mastered the concept. Thi

I completely agree on that - it's exactly like math, the only way to truly learn it is to practice, over and over again, until you've mastered the concept. This is something I'm coming to terms with in my career right now (~3 years in) - do I learn something to a mastery level, even if it's not the most marketable thing, or do I focus on breadth first and shoot for depth later.