I realized something perhaps similar which is that math is not literature. The only way to really learn anything is to go back and forth between reading and doi

I realized something perhaps similar which is that math is not literature. The only way to really learn anything is to go back and forth between reading and doing. Reading through a giant piece of code feels a bit like reading a math book and not doing the exercises. You'll get some good ideas and overview, but you won't really get "it".