Interest in Quality of Experience (QoE) has spiked over the last five years or so. Several large-scale research initiatives have been undertaken under a “QoE flag”, with interesting and useful technical results coming out of them. Despite all this, a suitable definition for QoE is (was, at the time of writing) still lacking. Everyone agrees on some aspects of QoE, such as its subjective nature, but yet a clearly satisfactory definition is missing. In this essay I present a proposal for how to come to a meaningful definition of QoE. Parts of this document informed the preparation of the Qualinet whitepaper on QoE definitions.