Couch and..

What is it about sleeping on the couch? Every night I put the kids to bed and think that I will just lay on the couch for 5 more minutes. At this time, I am not tired (or so I think), I lay down, get comfy with my book or some show that has been waiting for me to watch it and not even 5 minutes later I am sound asleep on the couch, with my contacts in and my clothes still on. This happens every night regardless of the time. I can work on my computer and stay awake forever, but the couch must have some sleep medicine in it. I will sleep on the couch until about midnight to 1:00 am... this is only after rewinding my show just to fall asleep again at the same part. I think that I must go to bed earlier or something must change in my mind to make me think.. just go to bed, even if it is 8:30.... :)