Sam's no longer in Hong Kong and his time zone is hours behind. So if he slept when he got back at the time, he'd be awake in the middle of the night. Basically, he's trying to fix his internal clock, but then he proceeded to take a nap soon after =]
it's not just a sleeping medicine, it's for cold,flu,sore throats, and such. They have drowsy ones and non=drowsy. But there's people i know that actually take it just to get knocked out since they cant sleep. You can be one of them