"Dinner is just about ready," I say. "It's time to clean up and come inside."

"OK!" she says.

A few minutes later I return. She is stooped over in the middle of lawn, picking up leaves one by one. The yard is still littered with toys.

"Eve, come on," I say. "You can play with the leaves some other time. You have to clean up and come in to dinner now."

"No! I'm not playing!" she insists. "I have to put the leaves in my collection!"

Around the corner, next to the crowd of tricycles and scooters, lies a little pile of yellow and green, fading to brown. She crouches down and places the leaf in her fingers right in the middle.

"Is that your collection?" I ask.

"Yes," she says. She's so proud.