Why does that happen? And where does that sock go? I dunno. Maybe this theory deserves another look:
It’s a matter of funding.
Anytime someone proposes a grant to study this phenomena, Big Sock puts and end to it.
Or something like that.
This observed effect is a result of the well known theory, “The Perversity of Inanimate Objects.”
The use of the elastics used to secure ponytails, to make pairs of socks mechanically fastened together prior to washing, collapses the phase diagram of the PIO state and thus overcomes the phenomenon.
Sort of like opening the box turns Schrodinger’s cat into either a live cat or a dead cat, upon observation.
By the way, only ponytail elastics work. Rubber bands do not work. This is, in itself, yet another mystery...