I have heard quite a few sonic booms so I'd like to think I would have recognized it for what it was and remained calm. However, I heard a recording of the booms on NPR during my drive home and I must say it sounded startlingly loud.

I think that your when you say you did #14, you are doing yourself a disservice. Even though it wasn't as conscious an effort as you would like to think, you probably processed a lot of sensory inputs and then decided to stay put. That is, you did #11. You didn't hear additional noise or loud sirens, see the lights dim, a bright flash or see other signs of distress such as people running down the street -- so why panic?