I was going to mention that, but he actually gets irritated when you re-phrase it that way too
and I can't figure out if maybe that's just him or if it's because the line of questioning in general is poorly received by others and they just don't say so openly.
I don't know if it's the same thing, sounds like it's coming from the same thing anyway, but there is also novelty aversion or in it's extreme form, neophobia, which is a fear/anxiety of new things / things you are not familiar with. Like a fear of heights, everyone has got some level of novelty aversion engrained in the lizard part of their brain, as it's the "unknown" that always presents a new danger so it was a useful characteristic for surviving. It's why we take a liking to the same coffee mug, and it happens relatively quickly (i.e. once you've used the same cup once or twice, you'll be more likely to pick that one over the others to my understanding), and partly why children are more prone to being picky eaters (food neophobia).
Note: I know very little of what I just wrote, other than Wikipedia and a podcast that talked about it, but I find it interesting.