I’ve only encountered that in Latin before: “vincit qui se vincit”. Or do you want us to fit it to a particular mythology it could conceivably apply to?

Well, when I read your quote it made me think of self-sacrifice or suppression of the ego in order to understand oneself and achieve a higher reward. Christ in the desert springs to mind (as does Christ on the cross for that matter). You could take the same story in the Buddhist tradition with the Buddha meditating before the tree of knowledge and resisting the three temptations (much like Christ.)

Another great example that falls more into the conventional notion of mythology or legend would be Odin hanging himself on Yggdrasil to gain the knowledge of the runes. "I was a sacrifice to myself, Odin to Odin." Odin actually had to die in order to return to the land of the living with the knowledge that made him the wisest, and hence ruler of the gods.

Or you could try the story of Gawain and the Green Knight from the Arthurian tradition. Here Gawain had to conquer his own fears of death and resist sexual temptations in order to conquer death; namely his decapitation at the hands of the Green Knight.

Thanks, thats the theme I was pretty much looking for.