I never prejudge based on categories like race or religion or gender or sexuality or any of the wrong ones, but I do have some that I use when working with new people. The biggest is "are they from Florida?" I can't tell you how many times I've had issues with people only to learn they grew up in Florida or they spent a significant part of their formative years in Florida. What goes on in that state that it creates so many shitty terrible people?
That's one of mine. Do you have any such categories?