Wittgenstein said something like ‘the world of the happy man is not that of the happy man’. I’ve always agreed with that, though I never knew what he actually meant.
But it is a supreme comment about the nature of human subjectivity. A single element can change. and instantly nothing is the same. And, being human, happiness/satisfaction is key.
But, I also believe, the world of the unhappy man is unlike anything else.