On the bright side, that particular kind of blathering signals someone who's probably self-aware and open to a similarly rambling, self-referential reply. So I'd feel OK parrying pragmatist's opener with something that's also explicit & meta-conversational, e.g.: "Ah, we're doing the having-a-conversation-about-having-a-conversation thing, and now I feel like I have to match your openness about your awkwardness, so I'd better do that: I find it awkward to try to manufacture conversation with somebody in a cramped, uncomfortable, noisy environment for hours. Fortunately, I mostly just want to sleep on this flight, and I brought a book in case I can't, so you don't have to worry about me nervously stealing quick glances at you."