There's a point past which it falls apart. I can just lower my expectations to the point that I don't expect my basic human such as food etc. to be met and be happy? Really?
The only way I have seen where this actually succeeds involves believing there is something better than this existence, available on the other side through the deprivation. And at that point, arguably, there is not a lowered expectation, but rather a new, heightened one.
I guess it really is dependent on personality, upbringing and other nurture of the person.