Answer:
I am tomorrow's yesterday and yesterday's tomorrow. What am I?
I can be simple or I can be complex. I can be found in this riddle or in everyday life. I can be shapes or even colors.
I have married many women but have never been married. What am I?
I run up and down the stairs without moving. What am I?
I am the kind of fish that chases a mouse.
What never gets any wetter no matter how hard it rains?