Man picks up a book about a 1930s/40s era magician from the table. (Think sleight of hand, rabbits, hats etc rather than your Crowley type magician) and says to wife: Wow! I must buy this book, this guy was an total genius!
Wife (looking slightly unimpressed): Really, what did he do?
Man: He was amazingly talented, he even managed to hide the entire city of Coventry from the Nazis during the war.
Pregnant pause. During which time wife and I exchange glances. The wife shuffles and giggles a little nervously.
Man (to me): Don’t you think that is amazing?
Me: Well….he didn’t really do a very good job, did he?
Man: What do you mean?
Me: Coventry was practically flattened during the war.
Man: …. Oh well, I’ll take the book anyway as it would have probably been a lot worse without him.