It’s hard to remember now, but there was a time when a rainy day presented an actual challenge to parents. The assumption was that on sunny days, children would be outside, playing in a kind of Norman Rockwell wonderland, no matter what the season. But when the sun disappeared and the rain fell, kids were cooped up indoors, bored, grouchy and itching to let off steam in the kind of activity that often resulted in raised voices, frayed nerves and broken lamps. There were even activity books, called “rainy day books” that prudent parents kept in reserve against their...
