This is a great recommendation, at least for middling programmers like myself. Every time I've been forced to dive into a third party library to understand how

This is a great recommendation, at least for middling programmers like myself. Every time I've been forced to dive into a third party library to understand how a certain case is handled or how a poorly documented feature works I've come out more knowledgable about the language, what I'm working on, and programming in general. The key of course is to really try to understand what's happening, not just peruse casually.