First of all, it is not possible to protect every single invention with a patent. To protect an invention with a patent, it must be 'new' and 'industrially applicable' and on a level that exceeds the existing State of the Art so far. For an invention to be new, it is obligatory that it wasn't declared to the public in a written, oral or another way before the Patent application. The invention will exceed the State of the Art if it reflects something that a person with a specific field of expertise can easily think of or talk about.