In physics, the Principle of Locality states that an object is influenced directly only by its immediate surroundings. This could be transformed to a simple mathematical statement of NO wisdom at all. Nevertheless, with extravagent assumption (on the obvious truth) and fascinating explanation (of the ultimate nonsense), the Principle may become a big Law/Theory/Theorem or a tremendous Paradox to shake your heart/body.
This is an expository talk of my own adventure in the quantum wonderland (concerning the structure problems of direct sums and tensor products). No working knowledge of quantum information is required in this talk.