I have 100% set myself a "no side quests" rule while going through the book so that I don't do that. I've had... patchy success with that, but I think I'm doing pretty well apart from the week I spent getting LaTeX rendering working on my blog so that I could do the pretty maths in that post.

What I'm doing is building up a list of things to dig into in depth once I've finished the book. Kind of like a treat to encourage me to push forward when I'm working through a bit that's tough to understand.