A theory about memory

Right off the top I'll own up to the fact that this isn't going to be ground-breaking or earth-shaking. It wont be written up in JAMA or any of the other medical acronyms, and you've probably thought it yourself a few hundred times, especially if you've reached at least your third decade and even more so if there are little people running around your house.

My theory is this:  the brain has only so much accessible space for memory. Not only that, but the bits of memory are actually categorized and sorted: multiplication tables, useless school stuff, names (subcategories: people, things), to-do (subcategories: short-term, long-term, don't bother), song lyrics from the 80s... and so on.  You get the idea.

One of those categories is geography, which encompasses directions, place and street names, and Tim Hortons locations.  Most people will probably never reach the maximum space set aside for geography, so they will always be able to retrieve the name of the street that Cousin Sue lives on, how to get to the dry cleaners, and the capital of Mozambique.

I've exceeded my allotted quota for geographical memory.  It's not because I read the atlas from cover to cover, or watched every season of the Amazing Race.  It's because I've lived in over 20 places and my brain is overflowing with street names, postal codes, travel routes, images of the houses I called home... argh! To further complicate matters, I've lived in one place twice, and another place three times, so chronology is becoming an issue as well.  Can Alzheimer's be triggered by things like this, do you suppose?  I try to do crosswords regularly to stave it off, but I worry.

This was prompted by my drive home this afternoon.  I was on the highway (being pressed for time) and drove past an exit which drew a complete blank.  I stared at the name of the road, and could not for all the tea in China place where that street was.  At all.  I scanned through three of the last places I've lived trying to imagine where that road lead, what was at the end of it, and which house was I going home to? I kept thinking the name was familiar, but I couldn't even think of the road I was to get off at.

That happened in a flash - by the time I could see that road sign in the rear view mirror I was properly situated on the right page of my mental map and got home in one piece.  So far I'm not a threat to anyone on the streets, so you can all breath easy.

Is it possible to get a thumb drive for the brain?