Wow I wish my parents had started me when I was in third grade!
I didn't start playing percussion and cello until I was in 5th grade. I played cello until my 8th grade year (that's 6 years ago that I stopped), but every once in a while I like to play around with it.
I have been playing percussion for almost 10 years now, but not actively since i graduated HS two years ago. I had some success at region/all-state bands but now I suck :/ I have no more chops and regularly get showed up by kids who still play.