A WORLD OF MY OWN

Came across nice kids poetry while polishing my calligraphy skills. It was used in Alice In Wonderland (1951) movie, however not a part of famous novel by Lewis Carroll. Two nonsense creatures came along with the writing. 

If I had world of my own,
Everything would be nonsense.
Nothing would be what it is
Because everything would be
What it isn't.
And contrary wise what is,
It wouldn't be.
And what it wouldn't be,
It would.

You see?