Answer:
I am constantly overlooked by everyone but everyone has me.
Lighter than what I am made of. More of me is hidden than seen. What am I?
I'm simple for a few people, but hard for them to hear. I live inside of secrets and bring people's worst fears. What am I?
I'm written with two letters, said with one and seen with two. What am I?
I have six faces but not even one body connected, 21 eyes in total but cannot see. What am I?
When is it bad luck to see a black cat?