Is the power of acceptance something that saves people in these situations? I guess it's like when you want to stay awake, to watch a movie, but you're just so tired you accept your situation and fall asleep. My experience when I do this I have a really good sleep.

I'm not saying that it's going to be a nice thing, I just mean, that calm feeling of acceptance probably helps people out and as others have said, the mind adapts to the situation. At some point one would have nothing to lose I guess, so they just go along with whatever they have.

Solitary confinement on the other hand is probably harder to accept, because I guess one would feel like "something can be done" about the situation, your torturer, prison guard or whatever could let you out, but they're choosing not too. Sunlight is just behind a door which cannot be opened.