I like how it is vaguely confirmed that some of the knowledge about stuff is there, however craftsmen are being secretive about it so it's not spread around the world.
He's really weird.
How would you react if somebody paid you some coins (for some thing you were selling) and then told you the coins were from a coin pool where some dude washed himself butt naked. There's a non zero chance that some coins touched his groin or worse.