Conversations evolve… and digress. My freshman comp English 101 professor was a brilliant PhD from Princeton (his dud brother was, too, and became a seminary president), and I remember two things about his teaching style – he talked really fast so you had to really listen hard, and he didn’t talk in circles but helixes, because he digressed a lot but always got where he was going. 
ETA: Oh, I guess I wasn’t referencing the same reply as you… but I won’t present a soliloquy like we’ve come to expect here.