Wow... I have recently taken courses that taught Baye's Theorem, and even more recently read a long, well-written piece about how even qualified people often misinterpret statistics (the way your parent did which is not congruent with Baye's theorem), and yet I still interpreted the stat in the same, incorrect way.
That seems to be one of the major laments in Thinking, Fast and Slow (Kahneman). Us humans, even when we're 'ready for it', tend to be remarkably inflexible in adopting concepts which conflict with our basic or social intuitions...
