Parents at work

Sheer genius.

Step one. Have a child.

Step two. Let it grow to the age of four.

Step three. Let it discover the world.

The world being a small pool in the middle of Bristol that's not supposed to have any bare feet in it.

The pool containing several large pieces of broken glass which the child is picking out piece by piece.

The child has bare feet.

No parents in sight.

Sheer genius.