I have this thing where I accidentally memorize license plates in the same way you might accidentally memorize what car people you know drive. It's a completely automatic process just like everything else we effortless memorize throughout the day. And, I've never thought about this before, but the cars themselves actually don't stick very well. Bill says it so casually that I wonder if it's the same for him.

I grew up near Microsoft, and it might help to know that until recently Washington plates for standard cars have all been 6 characters long in the form 123-ABC or ABC-123. On top of that there are a ton of common patterns on the road at any given time due to the way they are distributed. So they are pretty well designed to be memorable.

As an aside: We're now on a 7 letter system in the format ABC1234, and that's most of what you see on the road. These don't stick quite as often -- I can't tell if that's the format change or if I'm just aging or more often lost in thought and not noticing the world around me or what. I believe they all start with A now, so it's not actually an extra letter to memorize, but I think the format change modifies the rhythm to the plate and makes it so it doesn't automatically chunk and therefor doesn't automatically get memorized. I guess trucks (before this change) have always been something like B12345D (where it's always B and usually ends with D, I think) and those didn't stick very well, either.