Not too much and Not too little, but Just Right
I think everyone should wake up rested and refreshed, naturally, every day. Like to the cock's crow or whatever, say sunshine beaming on your face, not some crazy alarm clock that you smack to death every morning, possibly in the midst of a really interesting dream.
Anyway, according to the National Sleep Foundation, only about half of adults in the U.S. get a good night's sleep every night. Lost sleep links to poor work perfomrance, auto accidents, relationship difficulties, and anger/depression.
Maybe you only need 5 hours, and you think you need 9 or something. Seriously.
18 hours ago