On this forum, I would nominate many but clearly Entoman and probably Sayfu and Gonzo as well would qualify in all major categories mentioned!
Authorities darken council. An Authority is a person engaged in the invidious business of stereotyping and disseminating information, frequently incorrect... It was not until I realized this that my reading became any use to me. Up to that point I had been swallowing wholesale, with my facts, all sorts of fallacies and inaccuracies, alike in the matter of dressings and their use, and what they were intended to represent. From that point on an author became merely a suggester of experiment - a means of testing and checking my own observations by the water side, and no longer a small god to be believed in and trusted as infallible. And that is all an author, writing on any progressive art or science ought to be.
G.E.M. Skues, The Way of a Trout with a Fly
I'm flattered, A-man, but I respectfully decline the nomination. I agree with Mark that fish and not fishermen are the best judges of fly-fishing expertise.
OK, now I've read the whole thread (wanted to post my own definition without having read everyone else's). Some of the points made remind me of a line from Plato's Apology of Socrates, in which Socrates concludes after conversing with a man purported to be wise: “Well, I am certainly wiser than this man. It is only too likely that neither of us has any knowledge to boast of; but he thinks that he knows something which he does not know, whereas I am quite conscious of my ignorance. At any rate it seems that I am wiser than he is to this small extent, that I do not think that I know what I do not know.”