Cause the song is catchy and has a tendency to stick like a bad virus and... OH DEAR GOD! IT'S IN MY HEAD AND WON'T GO AWAY!!
I know how to stop certain songs from sticking in one's head. Unfortunately, it causes different songs to get stuck in one's head.
Yet another Touhou fan in the playground.
I'm the strongest, but don't call me an idiot or I'll cyro-freeze you together with some English Beef. - Cirno Avatar by me, assassin8⑨