I procrastinate on hard problems for months. It works. Many more mathematical scientists I know do exactly the same thing on occasion Mostly, in order to make

I procrastinate on hard problems for months. It works. Many more mathematical scientists I know do exactly the same thing on occasion Mostly, in order to make progress you need to work at it a lot. Sometimes, however, you need to go away and let it churn away in the back of your mind before trying again and revisiting it with fresh eyes and new knowledge but with your old familiarity. One of the most useful pieces of advice I have ever received was 'try to procrastinate from work with work'. There's something about knowing that the solution to the problem exists (but you don't have it) that really motivates detailed study but will slowly drive you mad if you're not careful.