I grew up poor in a fairly cosmopolitan city, and I still felt like I was going to crawl out of my own skin the first time I went to a slightly dressy business event. I have no fucks to give anymore, but back in the day, this would have probably been a fairly reasonable disaster preparedness plan if I had to be invited to something formal with a lot of social expectations that I was not familiar with.

It’s walking into a different culture, and while the hosts should be understanding, it can be reasonable to prepare someone who isn’t familiar with the culture before sending them in. Still, no need to be a dick about it.