I don't consider myself a "5% programmer", but I'd definitely agree that one of the big measures of my improvement as programmer had to do with my ability to qu

I don't consider myself a "5% programmer", but I'd definitely agree that one of the big measures of my improvement as programmer had to do with my ability to quickly figure out how a system works, and my ability to manage the mental models involved. Compared to who I was, say, ten years ago, I'm better at grokking the system in general. But for many projects keeping the entire thing in my head is impossible, so another thing I feel I've gotten better at over time is how to figure out which part of the system I need to hold in my head as I work on things.