My interesting ideas almost always come to me when I'm trying to sleep or when I'm in class. However, the subject of my idea is almost always unrelated to sleep

My interesting ideas almost always come to me when I'm trying to sleep or when I'm in class. However, the subject of my idea is almost always unrelated to sleep or to the subject of the class at hand. I think the meat of an interesting idea comes from exposure to the widest possible variety of environments, and the intersection between them. An obvious pattern for programmers which fits this criteria is an app idea arising from the intersection of knowledge about software and knowledge about something entirely unrelated, eg. patio11's Bingo Card Creator. (Yes I know, "interesting" is subjective.) The ideal "idea generating formula" for me has therefore become seeking exposure to interesting (no, actually just different) objects/places/people/ideas/pastimes/jobs/[insert noun here] and then waiting for my brain to make connections out of it while it should be focused on a lecture or sleeping.