Usually, in my experience developers are:
So, if you're doing things that others don't understand in a non scientific field, usually it leads to the impression that all others are "idiots", which leads to the reverse conclusion "I'm so smart", which is basically arrogance.
And the second dynamic is that at the beginning you have to appear as a "genius" so you get the job, which changes with experience, the hubris goes down usually.
So I would say "Everything that would make me look dumb or incompetent"
It took me years to just accept, and say that I:
These are actually good thing to say, not bad things. The illusion that we have to know everything is just ridiculous and it's fed by the industry and our surroundings.
We're just humans and it's okay to screw up, it's not okay if we don't learn from it!