I have always had a lot of trouble falling asleep, but for whatever reason I only have that problem in my bed-- some subconscious part of me feels like I *have to* go to bed there and that pressure breaks my circadian rhythm.
Falling asleep on the couch however is forbidden, decadent and delicious-- you are not supposed to have randomly conked out there so its powers to make you sleep are so much stronger. I consistently sleep better on the couch than in bed.