...when you realize that you can indeed slide down the metal pole into the cement shoe at the park. You didn't know you could do it, but when prompted by your mom (and you saw all the other kids doing it too...that was probably the REAL reason), you gave it a try. And lo and behold, you did it well!
And over, and over, and over again.
I love catching these *real* smiles, true joy all over your face.