What is Fintan?
1.
Irish name derived from the "Salmon of Knowledge" an old Celtic mythological story. King Fin turns into a Salmon to escape his enemies amd eats the hazelnuts that drop from the tree of Knowledge into the river. By eating them he has ultimate Knowledge. Eventually he gets caught and cooked the cook (Fin again in a new life) burns his thumb on the cooked fish and sucks it. He then knows everything.
As above example - no more to say