Mmm, I'm probably one of them. But the first time I just tried pend because there was a possibility of its existing when pending was so well-known (sorry, too tired to put that more elegantly). Once accepted, it was such a short and easy word that I usually remembered it when it came up again, like a number of other short words I didn't know before Chi, e.g. nori, inro. It's a bit like ired or iring, which I think are accepted as rare and I would have guessed at only because ire isn't rare.