In this article, I go deeper into the educational meaning of tiredness. Over and against the mainstream view that tiredness is an impediment for education, I show that this phenomenon is intrinsically meaningful. My arguments are based, first, on a detailed phenomenological analysis of tiredness, as proposed by Buytendijk. Tiredness can be defined as the point where lack of willpower and lack of ability become utterly indistinguishable. Second, I turn to Agamben's genealogy of the will, which shows that willpower was invented in order to control a more original, but also more arcane sense of what it means to be able to do something: (im)potentiality. I argue that tiredness, as analysed by Buytendijk, is a state of (im)potentiality. As such it has the power to interrupt the contemporary ordering of society and of the realm of education, which is fully predicated upon individual wilful self-commandment. More positively speaking, tiredness has an important educational value in that it grants the opportunity of beginning anew with the world. This article is also an attempt to show how phenomenological work and genealogical approaches can inform one another.