I always read in trip reports about people waking up at 3am and not getting back to sleep from wind or about people not sleeping because of this or that, but oddly enough, I never have that issue. Nothing like being high up with the wind ripping and sounding like a jet engine but it's so cold outside your bag you grab the piece and burrow into your bag and box the sleeping back in all it's perfect coccoony warmth, going right back to sleep not to be woken again until the alarm goes off. Or so I've heard. Forget about Ambien.
A month ago I was at trail camp sleeping soundly before waking up at 4am to drink coffee, burn some fern, and watch an episode of The Office on the iPod before leaving for the summit, all without leaving the warmth of the sleeping bag.
Or how about when you step out of the tent and its 0 degrees with a slight breeze and pitch black out and you have all your cold weather gear on, covered from head to toe with space age materials looking out over a cold desolate landscape. I always think to myself, "Man, I feel like I'm on the moon right now!" and then it only gets better as you head out with 50 feet between you and your buddy's headlamp and perfect solitary silence as you crunch across the snow. I always feel like a Moon Man for alpine starts.