Back when I was writing with Nom de Plume I had a character who woke up in a hotel room, with no memories and a note regarding her brainwipe that said "It's better this way."

I'm not sure that the note actually works as intended. In Planescape: Torment, the Nameless One is the main character and the point of the game is rediscovering what he's lost and forgotten. I'd think leaving a note would cause curiosity, remind that something was forgotten, whereas actually forgetting means it'd never enter the thought processes.

Interesting wager. I'd have to think about it. I'd be unlikely to play poker for memories though, I tend to lose.