Many men who had military service wear black socks no matter what color their trousers. The military issued black socks for every color - khaki, navy, olive, etc.
So those who have served think that's the norm. I can't believe that Matt was in any military service, but maybe he learned sock etiquette from his father.
Anyone have his e-mail, I'll write to him and set him straight!! Maybe I should mail him a copy of the CD-rom Encyclopedia of Mens' Clothes!