I've never heard anybody ever say "Mental Cavity." I started thinking about teeth. But I love this new terminology, mental cavity. Interestingly enough, some say the brain uses some kind of holographic mechanism for how memory is stored which then ironically adds credibility to how you're wording it. I kind of feel like it is a pun to cavity as there could be holes both physically speaking but also in the sense of trying retrieve and remember and recall memories. Strangely, everything is a hole or a bunch of space at the atomic level of things. But that's just the nerd in me speaking. Pretend I wasn't here. I kind of got sucked into the vacuum of your blog. I'm trying to climb right now. But will probably be back someday.
RE: Confusion.