I haven't actually read the online book (I did read the chapter on the Game Loop that's referenced in this article but this article is a really cool story about creating something really massive.

I really like this piece of advice and agree that this is how you get things done:

Around this time, I’d stumbled onto that article about Jerry Seinfeld’s trick for staying productive. It’s pretty simple: work on it every single day. Don’t break the chain of sequential days.

http://journal.stuffwithstuff.com/2014/04/22/zero-to-95688-how-i-wrote-game-programming-patterns/