Seriously?

how is it that something can wake you up in the middle of the night, hours before you have to get up, and you just can't go back to sleep? i'm talking about those nights where you are so exhausted that you go to bed before 10, and crash. there's no WAY anything can keep you from sleep, even if there was a hurricane or tornado or a barking dog. Nothing should be able to wake you before you absolutely have to get up. for some reason, those are the kinds of nights where the inevitable happens and you look over and it's 3 am. maybe 3:25, but usually for me, i don't get those extra 25 minutes. so then your mind starts going over the previous days happenings, then it rolls into what you have to do later today, during the hours that you are SUPPOSED to be up. then the trying to make yourself go back to sleep begins, right? you tell yourself, 'i have to get up in 2 hours and i NEED to sleep some more.' i am convinced at this point, this is our downfall. once you start down the road of "counting sheep" you're screwed. so you watch the clock. it's 4:15. 4:22. 5:00... o.k. i have to get up in a half hour... 5:15. all right, i'll just get up and make coffee...zzzzzzz. THEN THE ALARM GOES OFF AND SCARES THE CRAP OUT OF YOU!!!!!!!!!!
why?