You might think my favourite Irish myth would be the one I used to start the Modern Irish Myth series. You would be wrong.
While I love the story of Balor of the Evil Eye, it's not my favourite. No, my favourite is the Salmon of Knowledge. Not only does it tell the story of a young boy become a veritable genius, not only does it break down the stereotype that the old man in a story has to be wise (after all - it's wisdom and knowledge he's looking for), and not only does it demonstrate that short-cuts to knowledge and power aren't always as simple as they might appear, it's also full of little twists that make it more memorable.
The young Fionn MacCumhaill, the namesake of Balor Reborn's protagonist, is sent to serve the poet Finn Eces, who proceeds to capture the Salmon. Fionn is told to cook the fish - because Finn cannot possibly do that for himself - with instructions not to eat it. Whomever first eats of the Salmon of Knowledge, the story goes, will gain all the knowledge in the world.
Fionn, in doing his job, prods the fish with his thumb to see if it is cooked. When he burns his thumb on a drop of fat that comes off the fish, he sucks his thumb. From that moment on, the Salmon's knowledge is within Fionn!
When the poet realises what has happened, he instructs Fionn to eat the entire fish. Some stories tell of the poet growing angry from Fionn instead, when he realises that he isn't experiencing any of the so-called wisdom that should have been his when he ate the Salmon himself.
The end result is the same, though: whenever Fionn MacCumhaill bites his thumb, he gains access to the knowledge of the world. This allowed him to become the leader of the Fianna, a band of heroes in Irish mythology, and ultimately defeated the fire-breathing fairy Aileen.
He was a hero of good-standing, and his "origin story" is one that has amused children for years. (And, it seems, grown men.)