A survey of the literature in philosophical aesthetics reveals no extended studies on aesthetic disappointment. If anything, the topic has no more than a tacit or implicit presence to that of aesthetic satisfaction. Yet we do suffer aesthetic dissatisfactions in the form of disappointment. In this essay I attempt to initiate a discussion of the question, why and under what conditions are we aesthetically disappointed? I identify some of the main ingredients of aesthetic disappointment by examining commonly relevant emotions, the expectation basis of aesthetic appreciation, and the role of adaptive preference formation in the cultivation of personal taste as a means of coping with disappointing experiences. I show that aesthetic disappointment arises when some actual object, scene, or event, upon being perceived, is immediately felt to not live up to the normative ideals of our personal taste, held in the form of pre-dispositional preference expectations.