Polymath or Know-It-All?

It is apparently not uncommon for people with Asperger's to be thought of as "know-it-alls." But what, exactly, is a know-it-all?

I have been called a polymath, a Renaissance man, extremely knowledgeable, and, yes, a know-it-all. What is the difference among these things?

A polymath is someone who knows a great deal about a great many things. I have published on economics, sociology, literature, theater, philosophy, psychology and neuroscience, networks, complexity, organizations, spontaneous orders, and morals. I have a B.A. in recombinant gene technology with a minor in chemistry, and I have two years of grad school in molecular biology; I have a M.A. in English; and I have a Ph.D. in the humanities, the dissertation for which was titled "Evolutionary Aesthetics." I am also the author of Diaphysics, a book that covers all of those topics as well as physics.

A Renaissance man is a polymath who is also an artist. I write plays and poetry.

Obviously, "extremely knowledgeable" is a general term for polymath.

So what about "know-it-all"? It is obviously intended as an insult. In my experience is it wielded by those who have lost the argument to my superior knowledge on a topic or who feel overwhelmed by my unrelenting barrage of facts on the topic at hand. That's when you get slammed with the epithet "know-it-all." Those who are accused of such ought to take comfort. Receiving the accusation is an admission of ignorance and defeat by the person delivering it.