When he was growing up in Toronto in the 1950s, Thomas Caldwell punched another boy, who was Jewish, at school one day. He told the principal his hand had slipped but he was "bugged" by an action he knew had been antisemitic, according to news site Buzzfeed.
So bugged that 60 years later he sought to atone for the act by taking an ad in the Canadian Jewish News to apologise to his victim, Howard Rosen.