There was something physically different about me. It was easy to see in the day and especially easy to see at night. Others would call me names and laugh at me. Then one foggy night the very thing about me that everyone laughed at was needed. In fact, if it weren't for my physical difference, the night would have been ruined for many children. All of the others who used to make fun of me were suddenly so happy that I was around. Yet I was still the same. Nothing about me had changed, but the way I was viewed by everyone else had changed. The others told me that I would go down in history, and they were right! Who am I?