I was riding my bike and suddenly a car door opened right in front of me. I missed getting completely knocked off my bicycle by a millimeter. The only sound i made was a quick, startled gasp of air. No yell, no angry expletive. The driver who had opened the door yelled out an apology as i just kept on riding.
I think i was more surprised by my reaction than i was by the opening door. At last, my instinctual response is now silence.