Sometimes, I get stuck on a problem and can’t solve it no matter how hard I try. Then I take a break, take a nap or go for a walk and when I come back I have the answer. Why is this? We need both focused thinking where we are concentrating on a single problem, and diffused thinking that comes at a problem from many different angles. Focused thinking is good for things you already know, but using diffused thinking when you get stuck is an excellent strategy according to Thomas Frank. I have found this strategy to be invaluable with difficult problems.