Things like that are what make it worthwhile. Not a lot of occupations have people make comments like that years later. I love being accosted at the grocery store, bank, ballpark by former students.
I found that it often wasn't the lesson that they remembered. It was some offhand remark, or the way you held them accountable, or called them on their behavior that they remembered. That is sad for me, for it seems that is the kind of thing the 'educational establishment' is trying to take out of the classrooom today.
Good on you, Richard!