Occasionally I discover things that real anthropologists already knew, and had I studied thus and such society in detail I'd have found this stuff out the old-fashioned book-larnin' way, but I have to say it's kinda fun to find oneself reinventing, say, tri-corner hats. (You don't have an umbrella, and it rains a lot or you're at sea or both, so you need headgear that will funnel the water off of you. This became apparent to me when I was out walking in the rain and my ratty old baseball cap was doing a shit job of keeping the water off my face. I thought to myself, "What I need is a hat with rain gutters, angled in such a way as to sluice the water behind me but not down my back ... oh, wait! This object already exists!")
Today I discovered that Roman numerals are all symbols that are easy to make with your hands. All of 'em. I, V, C, L, M, X ... D is probably the hardest, but even that one is doable. This becomes even more apparent when you know that old-skool IV is IIII. So V is the four fingers together with the thumb sticking out.
I am not necessarily right about these things. Sometimes the obvious answer turns out to be a red herring. But it just makes too much damn sense, ya know? I need to become best friends with a professional anthropologist so they can check me on my impulse hypotheses. Or I could just put them on the internet and my smart-ass friends can say, "Well, actually ...."