I have a strange way of storing and retrieving pieces of information in my brain. For example, I store numbers and names in different places. I can usually derive up to the first six digits of a person’s phone number based on where they live or work. However, the last four digits can pose an interesting problem. I sometime get confused as to whose extension I’m calling at work, even if I call them regularly. There’s a certain group of numbers that I call fairly often, a set that I don’t call much at all, and the rest I usually have to look up. If I call someone often, I look in my “often used numbers” list and can usually remember which group of numbers goes with whom. If I don’t call that often, I look in my “infrequently used numbers list” and then do my best to remember whose number is whose. It’s a bit like sifting through loose pieces of paper on your desk where you’ve jotted down numbers but no names. “Hmmm. I need to call Ashley. I haven't called her in a while. Where'd I put that number? Let’s see. 5555. Whose number is that? Okay, this one is Jim’s, so it’s not Jim. This one is Laura, so it’s not Laura… would it be weird if I just called it to find out? Oh, hey, Bill. I was trying to call Ashley. Sorry.”
Directions are a weird one, too. I seem to store new directions in something like
reverse polish notation where I memorize a list of road names then a list of turns. For example, instead of thinking “left on Altamont, right on Summit, right on High Point”, I think “Altamont, Summit, High Point, left, right, right.” And if new sets of directions contain “old” directions (directions I’m already familiar with) I make a note to access those in a different place in memory and only pay attention to the new part. Why waste precious short term memory on directions I already know when it’s the first few turns or last few turns that I’m really worried about?