  We argue that category theory should become a part of the daily practice of
the physicist, and more specific, the quantum physicist and/or informatician.
The reason for this is not that category theory is a better way of doing
mathematics, but that monoidal categories constitute the actual algebra of
practicing physics. We will not provide rigorous definitions or anything
resembling a coherent mathematical theory, but we will take the reader for a
journey introducing concepts which are part of category theory in a manner that
the physicist will recognize them.
