When you select a locker in an empty locker room, the next person coming back to their locker will be right next to yours. If they happen to enter at the exact moment you're putting on your underwear, then their locker will be on the opposite side of you and they'll have to shuffle by uncomfortably close.
Me: (putting on underwear in the locker room)
Next guy: oh hi, I need to slip past you to get to my locker; hope you don't mind.
Me: No problem; it's Murphy's Locker room Law.
Next guy & Me: chuckle chuckle chuckle