Platos theory of forms

Our idea of what is perfect and how something looks is like a theory in itself, simply because we are familiar with something and its appearance it is thought of that it should always look like that and always be the same. But the idea of something being perfect is not necessarily one that occours.

"Everything on earth, whether an object (such as a car) or an idea (such as justice), is actually an imperfect copy of an ideal and permanent “form” that exists somewhere, beyond our universe. This is known as the Theory of Forms."

Duplicate things are actually just copies of one original, for everything to be the same and identical this must take place. When something happens it is just like a copy of something else that has already taken place further to the world. 

Plato believes that forms are real outside of out universe, ones that are not in existence in our world yet and what takes place in this world is like a mere copy of what is happening outside of the universe.