We judge people like we judge books
A friend bought me a book last month with a dull cover, there was no graphics, a plain font. I set it aside for two weeks before finally opening it and by page four I was all in with the book. This is how we treat books and a wise man said people are like book, I think we treat them like that too.
We have a man who sits at the office by the window who does not say very much to anyone. Everyone thinks they know who he is, but nobody has ever asked. He has worked there for three years and still gets referred to as the quiet guy, and this is seen as a complete definition of a person. I am just as guilty of this as well. Read the cover and close the book.
You also have the people who are expressive and full of energy. You prepare yourself for the excitement they bring. About halfway through the second chapter, you feel disappointment, there isn't much substance to the book. This feeling doesn't usually result in anger but more of a recognition of our naivety. Like book covers, people dress in ways to attract our attention or repel us, some people wear sombre looking clothing, so that we do not expect too much from them, and some people wear bright, colourful clothing with loud colours, so we do not get too close to them.
One book nearly caused me to skip, has led to changes in my reading style, the same with the person I almost dismissed before reading their book. I will continue to judge based on the cover of a book, but I will be working at waiting for a while before I make my final decision on things I see. That's my epiphany last night.