"Er, ordinary?" I replied.
Unsatisfied, she demanded ocular proof, and on examining my hard palate cried "Aha!" in a very significant tone. By this she meant, it turned out, that it was like her own - i.e. that my hard palate was markedly concave, and that any homunculus who might find themselves wandering around on my tongue would find themselves staring up at it as at the vaulted roof of a gothic cathedral.
"Isn't that normal?" I asked, confused. It occurred to me that at no point in my life had the subject come up.
According to her boyfriend (himself the offspring and brother of doctors) it is not normal: most hard palates run pretty horizontally back from the top of the teeth. Indeed, people with "high-arched palate" (for it is graced with the title of "condition") are prone to all kinds of minor annoyances, from crowded teeth to sleep apnea - to both of which I plead guilty.
I felt a bit like Molière's bourgeois gentilhomme on discovering that he had been speaking prose all his life, or perhaps Tony Hancock on being informed that he was AB negative. But even now, I'm not sure whether this is an unusual thing. I can find nothing on the internet about the incidence of HAP (as I feel I must call it). Is it really rare, or is it on a par with being left-handed, say?
Of course, what I'm really asking is, what's the roof of your mouth like?