Kahneman showed that people tend to think on their life in terms of generalization that are inaccurate if we look at their actual moment to moment experience.
If you ask someone "how happy are you" he will look much more at his salary than at his amount of annoyance at work. He looks of the story "how good is my job?" and not at the relevant experience on a momentary base.
Same problem applies to the understanding of other's experience.
We tend to define a situation in generalized terms.
A trip to Paris must be a great experience. Working at the supermarket as a cashier sounds negative.
The experience does not follow our streotypes. Some people have quite a nice time at the cashier desk. A trip when you are atressed as hell can be a terrible experience.
But nobody understands you when your feelings are out of the stereotyped response.
A vacation is fun. Point blank. Go argue.......
A person may even not understand himself in these cases.
Why have I suffered in this party? Something is wrong with me. I should try it again.
But why is the supposed fun of the party of any relevance?
Because we beleive these generalization and stories too much.
Life is the experience. And experience is not fixed by situations. Different people can feel very differently in the same activities. And between different times.