I was door-ed when I was 17. I was riding my bike to work. The door was attached to a 2 door Buick Electra 225 that had just parked at the curb. It looked pretty much like this one.
I was paying attention, or so I thought. I was watching the side streets, the cars in traffic ahead of and next to me, the traffic lights, the crosswalks. I wasn't looking inside the parked cars on my right to see if they were occupied. I do now, when I ride.