When you appreciate safety equipment......

Not a car but.....first new street bike. Even back then I knew to not get behind heavy trucks with dual wheels....just never know what may be wedged between them. Had bike and brand new helmet for a week. Driving down a 2 lane road, approaching a cement mixer. Was hanging back a bit...just about to enter a passing area....rock about the size of a softball got launched....cracked my brand new Bell helmet...gave me a concussion....