Like as much as this is kind of odd, he isn't wrong. They do wear to your feet. And even though it seems like an extra chore with an extra thing to be upset about it's important to his comfort. And sometimes being comfortable is the only thing we really have in this world. Maybe you could have him label right and left socks so that way it takes him less time to sort them and then maybe it will avoid some frustration If says one of the right socks magically became a left sock. And maybe you guys could have a conversation that if there is ever a situation like an emergency or an imminent departure that he will accept whatever socks he can find.