Answer:
What is it that given one, you’ll have either two or none?
It regulates our daily movements, but it feels no interest in our lives. It directs us when to come and go, but does not care if we pay attention. What is it?
Look into my face and I'm everybody. Scratch my back and I'm nobody.
I can be written, I can be spoken, I can be exposed, I can be broken.
To cross the water I'm the way, for water I'm above. I touch it not and, truth to say, I neither swim nor move.
When is it bad luck to see a black cat?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?