Although it hasn't been appearing with the regularity it once did, regulars at the jazz club in cyberspace called Fairfield Life have probably grown familiar with the term "Non-sequitur!," hurled at some other poster as if it were an insult of the highest order.
The Latin term non-sequitur technically means, "That which does not follow." What it means when hurled as an epithet is, in my opinion, "Wait. I am unable to follow you. You went too fast or too far afield, and I was unable to keep up." Taking a metaphor from the world of jazz, it's like being offered the opportunity to sit in with Heaven's Greatest Jazz Band. You plug in your axe, wait your turn, and then fire off your best melody. Even as you're playing it, Jaco Pastorius "gets" what you're saying so much he adds a bass line to it. Then John Coltrane takes your basic melody and mutates it, turning it into something even more magnificent. And then he "hands off" to Miles Davis, who rocks back on his heels and plays with the elegance of a musical Hemingway, taking the basic melody and not only re-expressing it in its primal essence, but then taking the melody and spinning it off into worlds previously undreamed of. Then Miles turns to you and smiles, and "hands off" back to you. And you stop the music and say, "Wait. WTF was that? I couldn't follow that! What have you done to my original idea? I insist that you go back and listen to it again, and then respond to it the way it *should* be played!" Just sayin'...