I have done some amateur research into the emotions. Many of them have pretty good descriptions that (partially) explain what these emotions are in response to.
For example, happiness is the ability to look at your past, present and future and compare them to your ideal. The more your ideal and your reality have in common, the happier you are. The less they have in common, the more unhappy and unfulfilled you are.
Humor is partially a response to the absurd.
etc.
But i have never seen any description of the situations which invoke ‘fun’. So what is fun exactly and why do some situations create this feeling? Is it something new, something dangerous, or what? What makes one thing fun and something else not fun? Why do we experience ‘fun’ when we do something dangerous or exciting?
From my experience, fun is usually something new, or something dangerous. But sometimes its totally mundane like just driving around with a few friends and laughing and talking.