muzak, not music

So I had a little conversation with a certain someone lately about music and how your taste of music might change at a certain age (I mean my taste did change a lot). He's alot into Hardcore and stuff still and I almost forgot that I just listened to that stuff years ago. I'm always wondering about how much your interest in music can change just in a few years. Why is that? Is it a part of growing up, is it a part how you were socialized or is it because you just gave up on something you believed in (which is maybe a part of growing up).
When I think back to all the different kinds of music I used to listen to, there is only one constant in my life and that is probably the music my Dad showed me. Just like Led Zeppelin, Black Sabbath, Ac/Dc and stuff. Since then I went from Rock to HipHop to Punk to Hardcore and back.
And thinking about Hardcore I had to realize that I don't feel connected to this music anymore really. But if I go back in time I have to say that the time when I used to listen to it was maybe the best time of my life. The shows, the people, the atmosphere.. everything. That was when I was 19-24 or something. I was full of idealism, full of ideas and stuff... and now it's just not like that anymore. So what happened? Shows have changed, people have changed, ideas have changed and I'm not feeling it anymore. But still there's a lot of appreciation I have for some Bands.