The only "surprising" concept in Monty Hall is that a game show host would do anything at all to help a contestant. I don't know if this is just an Americanism

The only "surprising" concept in Monty Hall is that a game show host would do anything at all to help a contestant. I don't know if this is just an Americanism, but the default assumption is this guy's trying to trick you out of your money. To explain Monty is helping you is, at all times, a stretch of the imagination.