This paper provides teachers and teacher educators with food for thought by developing a broad, contemporary re-evaluation of the often-used analogy between teaching and the theatre. It does so by synthesizing insights from scholarly works in education with insights from writing about theatre, including both historical work and published interviews with practicing stage actors. This approach throws into relief particular ways in which teaching does and does not resemble acting as described by its present-day practitioners. A key parallel is observed between the central challenges faced by teachers and actors: acting requires being truthful in imaginary circumstances, while teaching requires being genuine in artificial circumstances. Using work on bildung, the nature of this challenge is examined, and a call is made to help teachers and students better appreciate the intimate, reciprocal and shared nature of good teaching -- a challenge in a culture where corporate interests aggressively promote personalized and "anytime, anywhere" learning. The paper also addresses the phenomenon of massive online courses, which enthusiasts like to believe teach themselves. This idea, I suggest, is as absurd as the notion that a great theatre building could obviate the need for a strong cast.