Why does music sound better after another listen?

Generally this happens to me when I'm listening to more complex or weird stuff, so you're probably hearing details you missed the first time around -- I often get a bit sick of stuff I really liked the first time I heard it, since it loses it's immediate appeal eventually.

There's a lot of bands I love now that grew on me after I gave them a few chances. I often find that if music sounds great on my first experience with it, it doesn't last long before it becomes old.

Maybe its the complexity that makes music sound uncomfortable at first but a lasting impression afterwards?

This is different than music, but audiobooks are also a bit off-putting to me until after I listen to them at least two or three times. It's tough to keep up and fully absorb the information at first. Once you've heard it a few times you can pick up the parts you may have missed in much the same way that music sometimes sounds better.

This is the case with "technical death metal" or various kind of "avantgarde" music and the like - they sound better once you memorize the song and then, when listening to it again, you know and anticipate what fragment (notes, etc.) will play after the current one, and so on. Expectation of those "yet to play" fragments blend with the joy of what currently plays, that is, the expected joy from the future overlaps the joy of the present, also it seems you simultaneously reproduce the future in your head while also apprehending the present. Even in my native language I wouldn't be able to explain it better, unfortunately - I simply don't have words that would match this experience.

Now, I wonder if such things are discussed in music classes (I have never attended those, and yet I know there are people who dedicate themselves to the study of music theory), that is there are certain rules which are to be adhered if a track is to be catchy on the first listen, but since the rules are limiting, those who play avantgarde may even consciously ignore them. That is, they would be just like rules in Doom maps, there is a way to make map beatable on the first try, and then there are mappers who deliberately ignore such possibility and create map that require player to figure a strategy in many attempts, and the joy of playing such a map is in this figuring out what initially seems unfair or impossible, in achieving the task rather than in process. Think setting yourself a hard goal and beating it - such as running 100 km in 13 hours for the first time in your life (obviously there are people who can do it much faster) - it may be very painful, tiring in the process (it is impossible for a body to store glycogen for entire race), and then achieving it, which results in satisfaction that is a very different feeling from a fun jog of 5-15 km while conversing with friends.

The "other" tendency also exists (as mentioned above) - when you listen to something too much, especially in the background, you tend to lose interest over time. It tends to happen even faster if you specifically play track in the background while doing something else.