<p>When someone sees a color they have not seen before, or tastes Vegemite for the first time, they seem to incur some epistemic gain, one that could not be obtained through other means. This idea is at the heart of Frank Jackson’s thought experiment, in which a super scientist Mary comes to know all the physical information about color vision in a black and white room, from black and white books and television programs, but nonetheless intuitively learns something new when she leaves the room and sees a red object, such as a rose, for the first time. This paper focuses on one strategy for understanding Mary’s epistemic gain, according to which it consists in her becoming acquainted with something that she was not previously acquainted with, and a recent criticism of this strategy due to Torin Alter. I argue that Alter’s criticism does not succeed, and that he does not establish that Mary’s epistemic gain must involve the acquisition of propositional knowledge. I conclude with some general remarks on the acquaintance-based account.</p>