Is this common?

It's normal if you travel back in time ten years when people actually gave a toss about system of a down and korn. Actually that's not fair, korn would have to be fifteen years.

yeah, i find myself doing that too

i like your music taste, btw.

Haha your taste is awesome

Probably cause they don't like that kind of music but you have good taste in music if you ask me

Hell I sing ever fukin song even if I don't know it. Around everybody hell I was singing anti Christian rap at church once. Ha

It's normal. I do that too, but not in front of other people.

its probably because they have to hear the same song over and over and over and over and over. repetitive things can get very annoying.

Think this thing from your parents side. They have a wrong radio which plays only two songs, but it plays them all the time. Learn at least a third one (eg. Stevie Wonder - part time lover) probably your parents would like it.