not a party trick

if the water was in the shape of a square, i could drop the shape of a circle into it. if it was a circle, i could drop a square into it. it wasn't a party trick, i didn't understand it either. everyone kept asking me to do it again and again and i kept feeling surprised every time someone called out the shape before it hit the water and it worked.

the house was huge and there was a croquet game going on out on the lawn.