I think broadband is to blame. When I began writing The Case Against Q in the late 1990s, I was on a dial-up connection, and it was easier to impose discipline. I would just look up my references when I was next in the library, for example. Now, it is too easy to go and check them out straight away, and for one reference to lead one to another article I had not realized existed and so on. None of this is problematic in itself; it is just that the broadband era requires a great deal more discipline in writing practices, at least for me. I liked James McGrath's comment on my previous post, which I will repeat here, a great tip for graduate students and for easily distracted academics:
Your point about not looking up every last reference is also a good one. A nice trick I learned from my doctoral supervisor Jimmy Dunn is to put a sign $$$ in those places where one needs to go back and add a reference or further information. Since that sign has no other use, you just go back later and search for $$$ and track down the missing references then. It is a good way of keeping the writing flowing, even when one could theoretically stop and look for the needed citation.