As a kindergarten student in 1977, I set out every morning into the vastness of North Toronto. Having been ditched by my older brother at the first hill (he had a reputation to maintain), I would join dozens of other neighbourhood kids on the migration to school. We walked – or biked – not to be virtuous or to make a statement or to get a sticker when we got there, but because it was the obvious thing to do. A generation later, this seems like pure nostalgia. According to Ontario’s transit agency Metrolinx, the percentage of 11- to 13-year-old...