Experiences

What are experiences? What are they based on? How do they "happen"? I have started questioning this recently and have realized that I know so little of this basic tool for interacting with the world. Everything we do in forming ideas, learning something new, talking to some one has an interaction that could be considered an experience. Since this seems to be such a fundamental way that humans (and animals) are able discovery the surrounding world and react to it, then having the concept of experiences should be a fundamental feature of any artificial learning system. So how do we describe an experience? So far I have come up with this:

An experience is any interaction that consists of at least one memory/fact, at least one action and an outcome or result that is positive or negative.

This is a very simplicity definition but I think it also covers at least a majority of the concept of an experience in the most general terms. Does anyone else have any ideas?