What to do when you can't sleep

Why is it that you feel so tired one minute and then you are wide awake the next?  One of the worst things is when you know you have to wake up soon and that you should be sleeping, but you just can't drift off.  The more you think about it, the more awake you become.  I wish there was a way to unplug your brain and thoughts at night.  My problem is I might forget to plug it back in the next day, not that many could tell the difference.   Anyway, some of the ideas I have come up with to fall asleep are:

1.  Try and read in bed.  Problem with that is you keep your spouse tossing and turning because of the light on and the sound of pages turning.  

2.  Watch TV.  Yes, we have a TV in our bedroom.  I know a lot out there suggest that you don't have a TV in the bedroom, but my wife grew up falling asleep to the TV, so it works well for her, and it seems like the only way I can catch up on TV watching (mostly sports).  Problem is I get watching a show sometimes, which peaks my interest, and then I can't fall asleep until it's oven and then a new show starts.  Then I get into that one.

3.  Eat.  Not a good idea if you are trying to stay at a healthy weight.  Totally against Body for Life!  Plus then you have to brush your teeth again.

4.  Count to sheep.  Never worked for me.  I have got up well over a thousand, then I get bored and turn the TV on.

5.  Get up and exercise.  I have heard of people who do this, but I can't see it working for me.  It seems like it would just get my blood flowing faster and wake me up, not slow things down.

Anyway, I think sleep is one of the most crucial things to have for a well balanced and healthy life.  When I do get a good nights sleep, which seems to be less and less often, I always feel so much better though out the day.  Any great ideas out there on how to get your mind to shut off and sleep?  Sweet dreams!