The world is full of people who make assumptions about others based on race, gender, ethnicity or lifestyle, but even after all of this time has passed in the human civilization life cycle, a lot of people still don't seem to realize that everyone is not alike, nor do they have to be.
People who expect everyone else to act like them, believe like them and like all the same things they like seem to be extremely narcissistic, arrogant, xenophobic and self-serving. They have not awakened to the reality that they can't control how another person chooses to live, and the fact that their way of life is not the only way to live.
It's easy for some people to forget that every human being has feelings, no matter how strong or weird they may seem. So, it's just like that old saying goes about the word assume meaning it makes an "ass" out of "u (you)" and "me." Until we take the time to talk to or learn about another person in-depth, all we'll ever be doing is assuming things about each other , then trying to pass our assumptions off as truths.