While what happens to disappearing socks in the wash remains a mystery, here's a quick tip on what you can do with the spares. Take a sharpie marker and draw faces on them and pop them in your purse.
The next time your child fusses in a long line or waiting room, pull them out. Just the right size for lil hands, these impromptu puppets should provide adequate entertainment until the end of the line. And, if they get lost — there will always be another one in the next load of laundry.