Hypnotists have been trained for hundreds of years to speak in a certain way that seems a bit odd to the untrained ear.  Sometimes, it even gets noticed, while often it goes unnoticed for many conversations.  Often someone who’s been hypnotized as no idea what was actually said, but they find themselves acting differently.

This is a skill, it can be taught, and can most certainly be learned.  Yet it is almost impossible to unlearn a thing.