I'm CONSTANTLY tapping my fingers- I can't stop XD why is this?

It's like I never stop tapping- I tap on the desks in school every day in every cl and I tap at home and even when I'm walking I'll tap with my right hand on the palm of my left! And almost every time I tap it is to the same song- the guitar intro to MCR's Headfirst For Halos- and it's not even my favorite song! Is there any reason that I never stop tapping?