By the time he stepped onto a bus in downtown Toronto for the first leg of a trip to Lake Tahoe in December 2012, Geoff Hinton hadn't taken a seat for seven years. "I last sat down in 2005," he often said, "and it was a mistake." He first injured his back as a teenager, while lifting a space heater for his mother. As he reached his late fifties, he couldn't sit down without risking a slipped disk, and if it slipped the pain could put him in bed for weeks. So he stopped sitting down.

By the time he stepped onto a bus in downtown Toronto for the first leg of a trip to Lake Tahoe in December 2012, Geoff Hinton hadn't taken a seat for seven years. "I last sat down in 2005," he often said, "and it was a mistake." He first injured his back as a teenager, while lifting a space heater for his mother. As he reached his late fifties, he couldn't sit down without risking a slipped disk, and if it slipped the pain could put him in bed for weeks. So he stopped sitting down.