I was fitting an older man in a new pair of running shoes the other day, someone who seemed to have lived, as Thoreau put it, a life of quiet desperation. At least, his mood in the store was one of resigned melancholy — a former runner eager to share his regrets and warnings. “I do good to walk now and I would never recommend running to anyone, certainly not anyone over 50,” he said wearily as he slouched in his chair, his eyes scanning the dozens of bright shoes displayed on the wall. “The arthritis, the knee operations and replacements … it’s just not worth it.” He certainly did not realize the person fitting him in a new pair of shoes at that moment was 53 years old, had been running consistently for over 35 years and is still running three to four times a week, had never (knock on wood) had a serious injury of any sort, and finds running very much worth it. I said nothing, but simply took it as another reminder that older people like myself should be careful about making definitive statements on how to live based solely on our own fortunes or misfortunes. As Thoreau also put it, we really have nothing to teach the young — they’ll figure it out for themselves, as well they should. After all, it’s a new world every second.