I seem to the be the reverse. I attended very few concerts as a teenager/twentysomething. Now that I'm older, I attend more concerts in a single season then I did in total during my youth.
Take this year:
Prince, The Coors, David Byrne, Prince (yes, twice), Olivia Newton-John, Richard Thompson, Christine Lavin, and The Bobs.
And I'm not counting multiple times we see Avalon Rising, Brazen Hussy, Tempest or the bands at Lupin.
8 major concerts. Yes, I was a lame teen. :}