I find myself concentrating best when I’m taking a long shower or dancing to music with my earphones in (seriously). Somehow, both situations lend to focusing on the problem and coming up with a (usually) great and obvious solution.
On falling asleep: I have the opposite experience; I fall asleep fastest when I start concentrating on a particular problem.
On falling asleep: I have the opposite experience; I fall asleep fastest when I start concentrating on a particular problem.