You're riding your motorcycle down a residential street when someone backs out of a driveway without looking, right into your path. You clip the back end of the car and fly off your bike. Though you are wearing a helmet, you hit your head pretty hard on the pavement and wind up with a head injury.
A car runs a red light in front of you, and your motorcycle strikes the rear corner of the car. Both of you come to a halt with a screech of tires and metal on pavement. Then, before you can pick yourself up, the other driver guns it and disappears around the corner.