"Daddy, what's a mouse?"
"It's something that we used to point at objects on a computer screen"
"Just one thing at a time?"
"Wow! But how did you do this?"
[She resizes a square with two fingers and then touches the others to propagate the change]
"Well…in the past it was different. First you need to select all the objects you were interested in, by clicking in a space nearby, then dragging an imaginary rubber band around them all. If they weren't next to one another, then you needed to hold down Command on the keyboard while you clicked on each one. Then you would adjust the size of them with a separate control panel at the side of the screen. Or you might size one how you want, then press Command+C to copy, then Command+V to paste the squares…… are you listening?"
"No, sorry Daddy, that's all too technical for me. I don't know how you remembered all that in the old days!"
In the future, our children will all use rich multi-touch devices. They will look at the mouse & keyboard combination in the same way we today look at the Command Line Interface.