When I have a new code base that I'm unfamiliar with and need to understand it quickly, I'll go line-by-line and add comments about what I believe to be the int

When I have a new code base that I'm unfamiliar with and need to understand it quickly, I'll go line-by-line and add comments about what I believe to be the intended behavior. As I gain more knowledge I'll update the comments. For me explaining something I've learned helps me commit it to memory better, and makes sure I really did comprehended what I just read.