I'm almost 40. I sleep 8-9 hours a night (typically 10-6, sometimes ~9:30-6:30) and wake up feeling rested without an alarm. In my 20s I needed to sleep 10+ hou

I'm almost 40. I sleep 8-9 hours a night (typically 10-6, sometimes ~9:30-6:30) and wake up feeling rested without an alarm. In my 20s I needed to sleep 10+ hours a night or I was miserable; but I also pulled roughly one all-nighter a week. Can't do that anymore.