I asked another astronaut on here this question a few months ago, but didn't get an answer (not blaming him, I squandered my first contact with him by gushing over the fact that a person on the edge of space was talking to me, and he was swamped with many questions)

So my question is, how hard/easy is it to fall asleep in zero G? And are dreams affected in any way?

And if I may be so cheeky, I'd also love to know if anyone has experienced the effects of THC in zero G. For uh, research purposes, y'know?

Thanks!