This morning I noticed my mobile phone's battery was pretty low, so I decided to bring my charger with me to work. I rolled the cord up tight around the body of the plug and took it down to the car. I placed it in the back seat and it immediately began un-spooling, the potential energy in the cord releasing itself and sending my plug bouncing over the seat. Instead of stopping it, I thought to myself, "ooh, neat" and watched the cord tumble to the open doorway and leap off the side onto the ground where it cracked open with a snap.

I had about a good second or two to stop it, but no, my brain made the decision that watching my $15 phone charger acting like a spring was far more interesting than stopping it.