> It's most likely because you have twelve joints in your hands: three in each of the four fingers, excluding the thumb. I thought that was pretty nifty to discover. Like, I had never looked at my hands before, really. Hands are really wild, when you think about it.
Probably not. This explanation of duodecimal is really farfetched and I’m pretty sure it arose from someone staring at their hands desperately trying to come up with a way to count 12 on their fingers to explain this. (Ten fingers and two feet seems as likely.)
Clocks are (probably) divided into (two sets of) 12 hours for the same reason feet are divided into 12 inches. Because it’s convenient for everyday use. Subdivisions of 1/12th suck for complex math (if your number system is decimal anyway), but are great for lay use. 12 subunits captures halves, thirds, and quarters, all of which are very intuitive and very common in everyday use.
12ths are handy enough that we have a special word for “12 of something” (dozen) even though our numbering system is decimal.