One tidbit:
Unsurprisingly, falling asleep can take some getting used to. Just as you are nodding off, you can feel as though you've fallen off a 10-storey building. People who look half asleep will suddenly throw their heads back with a start and fling out their arms. It gets easier with time. One Russian crew member is renowned for doing without a sleeping bag and falling asleep wherever he ends the day. Anyone still awake after bedtime would see his snoozing form drift by, slowly bouncing off the walls, his course set by the air currents that gently pushed and pulled him.(Via Kottke.)
