While engaging in idle chitchat with my fellow housemates (one of whom happens to also be my girlfriend), I discovered that there are certain things that people simply don't want to hear. I'm not talking about obviously offensive stuff ("you smell", for example), I'm talking about myths.
Let's take an example. A common misconception is that going out with wet hair gives you a cold (you'll catch your death). This is simply not true. Going out with wet hair gives you a cold head. It does not somehow attract the common cold virus and cause it to fly up your nose on its tiny wings.
So I'm sitting there with my friends and we're talking about stuff and it so happens that my girlfriend has just completed her daily ablutions and has wet hair. Her hair is fairly long, so it takes a little while to dry. And she's planning on going out quite soon. So one of my other flatmates (who happens to be my girlfriend's sister) tells my girlfriend that she should definitely not be going out without drying her hair because she'll catch her death. Apart from the fact that a cold is not going to kill anyone unless their immune system is somehow fucked (which is not important because 'you'll catch your death' is obviously just a figure of speach), this is simply not true. So I say;
'You can't catch a cold from having cold hair. It doesn't work like that. You'll be fine. You'll just have a slightly cold head. Wear a hat.'
And the conversation stops dead. A get a glare apiece from my girlfriend and her sister, and the subject is swiftly changed. What gives? Have I insulted someone? Of course not. But I have challenged one of their myths, and myths are very powerful things (see religion, and mythology). People hang onto them, because they appear to allow us to understand the world around us. But they are, by definition, untrue. Hence any understanding of the world they appear to provide us must be false. People simply don't want to hear their myths challenged.
Not big news, I suppose. I just thought it was a good example.
This writeup just got voted down. Which I suppose proves my point.