Who Am I? Poem by Edward Schwartz

Who am I? nobody knows,
Neither a friend of mine, nor I,
Looking at the mirror, vow:
I have never seen this guy!
I was full of empty doubts
When was young and when was old,
Disappeared in the crowd,
Tried to change the existing world.
A silly Poet! The world is stable,
Its stability's for ages.
The Poet only writes a fable,
Which is being performed on stages.
Who am I? My mirror knows,
My mirror—brother, my mirror—friend,
My mirror—enemy, but always
Keeps my secret to the end . . .