Missing teeth

I decided to take the train in today, since it's the kids last week at daycare, and my niece was sick.  It took us 2 hours each way, thanks to 2 different late buses but it was a good end to our weekly public transit adventure anyway.  Ben, always friendly, struck up a conversation with some random guy on the train.  After a few minutes of small talk, Ben says "Why are you missing some teeth?"  (I started to jump in to spare the stranger's feelings, but figured I'd see what he had to say.  I was well rewarded.)  Nice guy explains it's because he didn't brush his teeth when he was little and he wishes he had brushed his teeth 2 times a day like his mom told him to.  Thank you train stranger! I'm sure that'll sink in a lot better than all my idle threats.