We had just moved to NJ several months before, into a new development. We were one of the first families in, so there was lots of construction going on all around us.
For a while, in the evenings, Gina and her dad would take a walk around the neighborhood, while I cleaned up from dinner or was preparing dinner. And on these little walks, they would find piles of stone and puddles of water and they'd toss the stones into the water. This became a daily ritual.
(I need to back track just a bit here) Gina had one of those Tupperware toys that all kids had... the ball with the shapes and you'd put the shape into the correct opening of the ball. So I taught Gina the names of all those shapes. This kid was so smart! She remembered the names of all those shapes, and there are 10 of them! (she could also say all her ABCs by 18 months and not only say them but could identify any given letter of the alphabet... but that's a story for another day)
OK, so back to the stones. So there is Gina and her dad tossing the stones into the puddle, and she picks one up and says, "Look Daddy! A trapezoid!" He was so shocked! He came rushing home to tell me that Gina knew this! He had no idea I had been teaching her the names of the shapes. Is my kid brilliant or what!