Why does everyone ume all Middle Eastern people are Muslim?

People always ume I'm Muslim when they find out my background. Then they automatically put me in a stereotypical category, when the fact is I have nothing to do with Islam and I could care less about religion personally! Why don't people realize that the Middle East is a diverse place just like anywhere else? I'm Lebanese and I actually have fair skin and green eyes, and many people from my country are Christians.