A friend of mine was up late night studying for an exam. She was getting increasingly frustrated as nothing was making sense to her. I told her to relax, go tak

A friend of mine was up late night studying for an exam. She was getting increasingly frustrated as nothing was making sense to her. I told her to relax, go take a nap, and when you wake up everything will make sense. Three hours later I get a text from her: "OMG thank you. The nap did help me understand everything!" (I'm paraphrasing). I don't know what it is exactly, but I feel like naps almost invariably help me to understand complex problems. I suppose it's partly because my brain is still thinking about the problems while I sleep, and partly because my brain wakes up energized and ready to go, without the fog of tiredness interfering with my thoughts. Regardless, napping when I'm tired has yet to fail me whenever I'm stuck on a complex issue.