What makes your dog smart?

tell us your quirky stories about how your pup showed his/her intelligence.. here's mine...

whenever i take sandy and sugar for a walk we usually bring a ball to play fetch while we're walking (we live in a neighborhood where you can walk your dogs without a leash without any worry) so anyway.. as we walk up hills, sandy will get ahead of me and she'll be sitting waiting for me to come get the ball, but instead of wait for a while she knows if she gently drops the ball down the hill it'll come straight to me .. i know this sounds kinda DUH but she started it at a very young age and always done it i just htink its a quirky little way she shows her intelligence! :D