This filing system is ..temporal in nature, that is, it files by date. I rather question this hypothesis. From my experience, the mind constructs "search trees" by association, weighted by emotional loading. Yesterday, at work, I had to talk English the whole day with visitors from another company, and at some point, I asked them, referring to some other firm: "Why do you want to sidestep them?" - I swear I had never used that word in my life. In the evening, I looked it up in the OED, and it means exactly what I wanted to say.
Sometimes words which you last used as a five-year old come spontaneously to your lips .