Arrignoramus

An ignorant or stupid person but arrogant enough to believe if they haven't seen it or heard of it, it doesn't exist.

The guys I work with grew up in the same 50 mile area, moving from out of state and being exposed to many cultures and diversity, I was floored when the arrignoramuses thought I was crazy when I said "pomegranate". I learned that these mythical fruits simply do not exist.