If you want to have a good attitude and feel happier about your life, then make sure you get good sleep. Your body needs it! Without sufficient sleep, sleep researchers say, your mental function becomes impaired: for example, insufficient sleep can negatively impact your daytime performance, causing lower levels of energy and duller thinking. Inadequate sleep has serious consequences. Certain regulatory systems and important organs continue their vital work while you sleep—in fact, researchers have been able to pinpoint parts of the brain that actually increase their activities when subjects are asleep. Getting adequate sleep enables you to wake up refreshed, energized, and in a good mood.