A language teacher is similar to a magician who tries to elicit an infinite number of things already present but hidden in the mind of a learner by helping to bring them out in the form of a new language.
To master this process the teacher needs to process the knowledge of diverse methods of teaching present and used in the past and stay up-to-date with current theories of learning. The present era of digitization of teaching, access to infinite sources of information through the Internet, and Big Data allows us to see things that we could previously only guess and theorize about. All these things require the modern teacher constantly update his knowledge and teaching techniques.