I think what notch does really well is keeping the task at hand interesting to himself. Even looking at videos of him programming minecraft, you see that he does it to entertain himself. If a certain amount of time passes where he isn't liking what he's doing, he probably switches over to something interesting and keep the hard stuff in small bites for later.

It's a very good concept to work by, keeping things flowing and neither bore yourself to death nor skip on the hard things.