So to sleep well at night, you need three things. You need to be emotionally, mentally, and physically tired. Emotionally tired means I was engaged today. I care about somebody, some things, some idea. It doesn't matter, but you put out some energy, you have a passion for something you're involved with life. Mentally tired means that you use your brain today. It may be that you worked hard or you're in school and you're learning something. Maybe you're doing crossword puzzles or some other endeavor where you construct yourself a little bit. Finally need to be physically tired in a way. This is the easiest one to understand. But unfortunately for most of America, it's not. When we do too easily, physically tired literally means that we got some exercise. We did some exertion. Maybe we built up a bit of a sweat and now the restlessness in the body is less and we're more likely to fall asleep at night.