Maybe I'm just weird. Listening to music that I don't know puts me to sleep really quickly because I can't sing along with it. I sing along with every song, everywhere, no matter what it is. I sing Japanese karaoke at conventions, and I have a group of people from around the world that sings Japanese karaoke on the net (it's funny because we are all from different countries, we don't know eachother's languages, but we communicate through our 2nd language of Japanese). Like I said, everyone I've known has sung along with OP/ED's as well. I can't be the only strange person here if they started including karaoke lyrics for OP/ED. If you're worried about sounding stupid so you force yourself not to enjoy OP/ED's then I would say you have your own set of problems. There are, of course, those songs that are just completely uninspiring in anime that I usually just skip (School Days OP, Canaan ED, FSN 2nd OP, Bakemonogatari OP, Higurashi kai ED, etc.).