Most people make their ideas and opinions part of their identity. And so if it turns out they are wrong about something then a part of them has died, or at least severely injured and needs to be healed. A few people are not like this and their ideas are more like a collection of trading cards they keep in their pocket. They think they have a pretty good collection but are not opposed to throwing out one for another if they find something more valuable.

The latter types are the only ones who you can have honest intellectual debates with.