“RE: (solution) The Little Old Man With Good Teeth and Shaky Hands: Puzzling Logic”

Very good, Thom. That you knew the roots of the puzzle sort of puts you out of my "target market" for this puzzle... I'm more interested in blowing the minds of people who haven't looked at it before.

I'm sure you'll agree, when the solution to a puzzle like this finally clicks, it's pretty exhilarating.

Did you catch my hint about the puzzle's roots?

Also, I've put "solution" in the subject of your message, since you forgot it. Hope you didn't spoil it for anyone!