Most of the falsehoods that most people believe, yourself most likely included, are things that they had not even noticed that they believed, so would never have thought to "test empirically", or even wonder whether they might not be true.

Your personal offense at the suggestion is characteristic of people who have been disinclined to discover their blind spots, and who stand to benefit most from an experience.

I have not seen people come away believing even more falsehoods than they went in with, although very large numbers can be hard to compare. It can take a long time and hard work to whittle that number down, but the best time to start is usually now.