When I was young, I had a lot of trouble sleeping. My mind got to racing about things - people that pissed me off, things I wish I would have said or done, things I wish I wouldn't have said or done, you name it. It was difficult to clear the mind. When I learned to "let go", and focus on breathing and catching and releasing thoughts, I was finally able to "catch my breath", so to speak, and this helped reestablish a neutral frame of mind that didn't get in the way of a good night's sleep.
It's interesting, because people talk a lot about their sleep "habits", but few people admit that often they really are just that; habits. I found a link to the following article at everythingstrength.com - it's a good one:
Save Yourself From Insomnia
Related Squat Rx Post:
Squat Rx: Sleep Debt