I believe because I have seen, and I have always been a logical, practical person. When I saw a young girl at my childhood home, I looked away once, saying to myself, couldn't be, looked back, she was still there. When I was a child, it never really scared me, I didn't know it wasn't normal. But it's strange, I've only seen people that I do not know, have never seen before. My husband and I saw a man at the cemetary, we were in the car, it was Christmas eve, i remarked that it was nice someone else was there too. He was standing in front of a grave, directly to the left of our car as we drove towards him, he disappeared. I screamed, we stopped and got out. We looked behind the larger stones, he was gone. My husband saw him too.