Here is a tip.
don't' watch something you are really interested in when you are exhausted. You will wake up surprised to find yourself in a place you should not be many hours later.

Last night I watched the Fellowship of the Ring with commentaries. In the afternoon I stayed up and watch the cast commentary and in the evening after writing here I snuggled down to watch the writers commentary. I figured I would watch for a bit and go to bed. Nope, I watched and fell asleep before the movie was out of Shire. I woke up this morning still on the couch with a crick in my neck and back.

I did have wonderful dreams of Hobbits and such. :-)