My mother and her grandkids

In cleaning off the washer today (which is where everything that comes off the table gets put at mealtime), I found a stack of cardboard shapes. Circles, oval, square, rectangle, triangles... Where did these come from, I wondered.
My son told me. "Look at the shapes we made with Grandma yesterday," he said. I had taken Madeleine to swim class and she looked after the younger two.

A couple weeks ago, she babysat while I went to my OB appointment. When I came home, they were sitting around the kitchen table playing Candyland.
"It was Madeleine's idea," my mother told me. "I told her that she'd have to teach me how to play, but it was pretty easy."

Why do simple cardboard shapes and games of Candyland make me want to cry?