ambien works eventually. for me it takes a long long time. I typically stay up and watch a movie or play on the computer after taking it. after about an hour you start feeling almost drunk. but you usually don't notice that till you get up to get something to eat. Oh did i mention it's a great way to gain weight! um, anyway, yeah two hours later you're sleepy and sometime after that it's blackout mode. you're start to remember things that you forgot you did....Like this cup of coffee I apparently had to have last night.
So I guess if you where responsible enough to take the medication, lay in bed with an audio book you would be fine if you can fight the urge to get a snack. Don't be out of bed at all, because that's when you can wonder, and sleep walk. the ambien is telling you to sleep, but your mind is still going a mile a minute. and the ambien almost thinks by putting ideas in your mind that would make you sleeply, like a turkey sandwich, or a bottle of beer.
In the morning it's much like waking up at a frat house party with nobody around. You just arn't sure what all happened last night, but there are clues....only clues.