The one on my shoulder? Fell off my bike trying to avoid a collision with another kid on a his bike, scraped my shoulder down to the bone on the pavement. The scars on both knees? Fell off a scooter while wearing shorts, hurt both knees pretty bad on the pavement (and spent weeks unable to comfortably bend my legs which made everything suck worse than the injury itself). The scar on my forehead? I was wrestling my little brother. Things ended poorly.