Lack of curiosity and learning. I hate being around people that aren’t trying to grow and learn, regardless of age. These are people that feel threatened by other people’s success, and never admit their own mistakes. It’s incredibly off-putting and sadly common, especially in business where I meet managers or executives that are so worried about not “looking dumb” that they never experiment or learn.
I’ve had wonderful conversations with people from different religions, political views, etc where things were civil and the topics interesting. The common denominator is that they are open to the idea that they are not “done” learning new things, so new ideas and information is not a threat, but a gift.
In contrast, the person who is “done” is never happy when presented with a new line of thinking or new evidence. This is seen as proof that they might be “wrong” and that is never tolerated.