In my drawer, I have accumulated 11 distinct types of sock, including one dress and one women's. Seven have no mate, and I can account for at most four of the different types.
I only ever buy one kind of sock.
We all know that the amount of socks you put into the wash never equals the amount you get out, though it's usually an odd number. Now, apparently, left to their own devices, they evolve.
I am convinced that socks obey different laws of physics than the rest of the universe. There is weird, weird stuff going on here.