Sometimes I am not the brightest bulb in the tree. My car has been sitting for a few days because I take the train into school during the week. Getting home, I decided to run to the grocery store and jumped in my car starting it up. Just then, it starts shaking and I look behind thinking someone is joking around rocking my bumper. Nobody there so I think it is idling rough, but then it stops.
Only at the store when someone comments on the earthquake did it all make sense. It happened over the hill in Berkeley and was only a 3.8, to the 4.0 that happened earlier in the day. I never felt that one either. Only in California would I confuse my rough running car to an earthquake.