This paper forms part of a larger project. The project and the paper might be located in the genre of philosophical archaeology. In philosophy we need to explore and become better aware of the past that lies under our feet or, to point a better metaphor, within our skulls. I want to remind you of an old puzzle in the history of theorising about knowledge. In the larger project I consider some ancient reactions to this puzzle; and I try to indicate the important influence of these discussions on modern philosophy, and to comment on the significance of Meno's Puzzle for contemporary epistemology. In this paper I shall concentrate on the puzzle itself and the reaction of the first person to comment on it. This is, of course, the same person who devised it, namely Plato.