I don't know if it's true, but there are some theories that before the industrial revolution, people slept in 2 phases (ie biphasic sleep), not all night straight. If you have a tiring job and/or you exercise a lot, the body may be tired enough to sleep all night. But otherwise, maybe it's being made into a serious "disorder" when it may not have to be. If you're retired and you didn't sleep all night, you can easily catch up on your sleep by taking a nap in the middle of the day. Just a thought before wasting tons of money on sleeping pills and getting too stressed out about it.
