Growing up, I always figured that classical music was better than popular music. My parents were are some pains to help this inculcate this belief. The message was never so much that popular music was bad, but there was certainly a general impression given that it wasn't as worth while.
However, there was very little classical music that I was all that into. Much of it struck me as slow and boring. Sure, there was some that I enjoyed. Something with sufficient excitement in it like the 1812 Overture or Prokofiev's Alexander Nevsky score or Holst's The Planets.
Through high school and even more so college, the only orchestral music I listed to tended to be movie sound tracks. And Brahms, for which I'd developed a taste, though no other classical composers interested me. Aside from that, I listed to all modern music: Cake, Smash Mouth, Barenaked Ladiews, Metallica, Creed, P.O.D., Coldplay, Dave Matthews' Band, The Beatles, you get the idea...
I think the style and themes of rock are inherently more appealing when you're in your teens and early twenties. Something is different in the speed with which you feel and think, and what you feel and think, that makes "rocking out" feel much more congenial than the more complex and subtle rhythms of classical music. (At this point, some purist may point out that "classical" music is really only stuff written between 1730 and 1820, but this person is being tiresome and can go shake their ears, because I'm not thinking of a better term at the moment.)
Somewhere along the line, however, something changed. It must have been at some point in the first year or so of our marriage, because I think I started to listen to classical music finally while commuting.
I hadn't made any particular effort to cultivate the like in quite some time, yet for whatever reason one day I flipped to the classical station and suddenly found classical music far more involving than I ever had before.
Again, I wonder if there's something that changed in the general tempo of my life, intellectual and physical that caused this to happen. Suddenly works which had seemed hopelessly "slow" and "quiet" such as Vaughan Williams and Debussy, or "fussy" such as Handel and baroque liturgical music seemed not only interesting but absorbing.
I haven't fully dropped popular music, though I don't listen to it as often as I used to. It's become something that only seems to fit with certain moods rather than being a constant underscore to life. And I find myself trying to curtail how much I listen to it around the kids, although they do have a few favorites, such as the Blues Traveller album they call the "angry cat".
I wonder how common this arc from more popular music in youth to more staid styles as you get older is. Goodness knows, I know a number of people much older than I am who remain fully engaged in the modern music scene. Yet, in my case at least, it seems very much a case of maturity causing a change in my listening habits that no amount of trying to appreciate classical music more when I was a teenager could achieve.