About feeling a bit old

Had the chance to hang out with some 15 y/o students and I felt kind of old, even though I'm just 10 or 9 years older. I don't play any videogames, I don't know who Hanna Montana or the Jonas Brothers are and I find Twilight and Edward Cullen pretty lame, so I can admit now that I'm officially getting old or maybe just old-fashioned.