Come on, man. If you're sporting ratty, to'-up boxers, briefs, or tighty-whities, how far do you expect to get in life? If you can't even take care of that which is literally the closest thing to the most important thing you possess, there's no way you can be relied upon to flourish in any other aspect. Overhaul the rotation every six months (a year, if it comes to that) and keep it moving.