Admitting you were wrong/made a mistake/can’t do something.
Related: changing your mind. The one thing that can still destroy any politician is the dreaded “flip-flop”. Yet the thing we most need them to do is to revise their position in the face of new information.
I think most of the problems in the world come down to some sort of bullshit posturing that (especially male) humans seem to be compelled to engage in.

Exactly the same here.
Plus, some people are really sensitive to tastes and textures. When we’re not them, we call them picky eaters. When I was a child, I couldn’t stand the taste of water, and there were other foods I found repulsive. Even a different brand of ingredient from the one I was used to made me gag.
Somehow, I completely grew out of that and I’m now very adventurous when it comes to food. But it did leave me with empathy when I encounter someone who has a limited palate, which is pretty common among my nerd-spectrum peer group.
When you think about it, eating the wrong thing is a quick path to sickness or death, so it makes sense that food can trigger extreme reactions of disgust. If you ever ate something and got sick afterward, even if the two were unrelated, it’s very hard to un-make that connection.