Overall, I do find I limit my own use of rare or seldom used words in conversation... especially when I'm arguing an idea. I think this stems from the awful discussions we had in English classes in university where too often fellow students spent time trying to impress others with their extensive vocabularies. There were times that the discussions became so convulted I felt most of the class wasn't even sure what the were arguing anymore.
So, I guess I appreciate a couple of words in a conversation that are unique or rare, but if what a person is saying gets lost in all those long words, well, they are missing the point of conversation. I can really appreciate a person who is able to say something succinctly and clearly... it's what you say that matters and impresses, not how you say it.
All of that said, how in the heck did Kat go through 20 years of life and never hear of the appendix, or appendicitus? Something about that rings false to me. I know that by that age I had heard of it numerous times.