you dont believe it? I didnt go to the doctors, My mom and dad picked out the gravel outta my knees. Sorry man, I THINK that there is gravel in my knees, there are small bumps in a few areas on my knee, and im pretty sure it isnt scar tissue, so I just figured it was gravel, what else could it be?
Yeah, my dad was chasing me down our driveway (it was gravel at the time, now its asphault) with a super soaker and I tripped and fell, skidding all the way down the driveway, tearing open my knees.
Sadly, the exact same thing happen to me about a month and a half later, but I was running down it for another reason. I cant remember why, I was 8 at the time so I dont remember.