According to the search results, Dumbledore saw different things in the Mirror of Erised at different times in his life. In Harry Potter and the Philosophers Stone, Dumbledore tells Harry that he sees himself holding a pair of thick, woolen socks when he looks in the Mirror of Erised. However, in Fantastic Beasts: The Crimes of Grindelwald, it is revealed that when Dumbledore was younger, he saw Grindelwald in the Mirror of Erised. Additionally, J.K. Rowling later revealed that at an earlier stage in his life, Dumbledore actually saw his own family, especially his dead sister Ariana.