I elect not to keep certain information in my brain because there is (presumably) only so much room in there. For instance, there are several procedures at work that we repeat annually, such as testing, orientation, stuffing end-of-year envelopes, voting on certain measures, etc. I won’t remember how we did certain procedures last year because it’s easier to remember that there’ll be a memo explaining the procedure for this year. Another example: I probably can’t tell you the relative locations of some of the towns near my alma mater, because it’s simpler to remember which major road leads to which town. It’s all about saving space on the hard drive.
Upon watching the BBC’s recent Sherlock series, I was pleased to learn that Arthur Conan Doyle, via Mr. Holmes, had articulated a similar belief. Holmes only keeps information in his noggin if it helps him do his job. Thus, he claims not to know the identity of the current Prime Minister or whether the Earth revolves around the Sun, as neither fact would help him solve crimes (though a bit of esoteric knowledge about a fictional supernova just happened to prove useful in a hostage situation). Great minds, me and Conan Doyle.
Then I recalled that another fictional character had made a similar observation about brain capacity, but I couldn’t remember what character. I remembered she had to prepare for something, and was trying to retain only the most relevant information à la Holmes. Did some digging around on Ye Olde Tyme Internet, and…
…it was Kelly Bundy from Married with Children. She had to cram for a quiz show about sports, and since her brain was already full, every new fact displaced an old fact. She lost on the final question.
That was a bit deflating. Great minds, me and Conan Doyle and… Kelly Bundy.