I've enjoyed your books and am a big fan of counterintuitive probability problems like the Monty Hall problem. There is a Dover paperback by Mosteller that has a number of such problems worked out. As I understand it, prime numbers make the best encryption keys. Composite numbers don't have these properties. It's interesting that the ethereal realm of number theory provides the intellectual muscle that underlies our international banking and military systems.
Many people do.
And I walk under ladders too. Twelve is nice, has lots of factors, and thirteen, by contrast, seems to be a spoiler and prime. The murky area of human psychology lurks here. That's all the time we have for this chat. There's lots of questions we didn't get to, but save them.