what's wrong with me?

as i was going home from tap class today, i couldnt help but wonder :

if i learn a lot of my dance steps through the rhythm of the music and how it flows with the music, it means i am most definitely musically inclined (this is especially apparent when learning tap - i need to hear the rhythm a few times before i can piece the sequence of steps. but after that the rhythm sticks in my head and i dont have problems matching it with the right beats in the music).

BUT the puzzle is - why then, am i musical (instrument)-ly challenged? i tried learning the piano and i failed grade 6. in fact, i might have narrowly failed grade 5 as well. but i aced the theory part. and did pretty well for the aural bits.

someone explain why why why? i can do syncopation in dance, but SO not in music...