Well I can give a technical answer to this. Till couple of years back I never wore socks with sandals, having read that this would make me sexually unattractive( I never actually did any serious research comparing success rate with or without socks, I just believed what I read).
   Anyway, then I decided to get involved in self-building a wooden house. Come the summer we were on teh woo work stage, and the big heavy stuff was done, so I ditched the steel-toed boots and moved into sandals. After on eday of walking about with sawdust between my bare feet and the sandal-soles, and with the cracks of my toes full of sweaty sawdust and opther detritus, I made the move to socks and sandals. And found them the ideal summer wear in conditions containing sawdust, sand, scattering grandpa's ashes, anthrax powder or anything similar.