I've got no other explanation.
I left the house for an hour to attend Little Brother's Vacation Bible School closing performance. When we returned, I found some onion peels on the floor, and the kitchen smelled like onion. Busy with lunch, I didn't ask about it.
But Middle Sister told me anyway. "I cut up an onion before," she declared. "I wanted to see if I would cry."
"Oh...so what did you do with it after you cut it up?"
"Well, some of it fell on the floor, so I threw it away."
"That's too bad. I could have used it in tonight's dinner. Later, you can cut up another one for me."
She agreed, announcing proudly, "It made me cry, too!"
So she can cry again later. Saves me from having to do it.