Language is failing Beryl Dusinbery. She is 99 years old and having trouble retrieving words. “One minute she has a word, then she hasn’t. Where does it go?” Conversely, Shimi Carmelli, 91, can’t forget.

One Shabbat, toward the end of the morning service, Tova Mirvis was stricken by a debilitating headache, in which “the pain concentrated along the line where my hat met my head.”

And then there is the appendix. You have turned the last page of Lucy Ives’s intricate, darkly funny debut, and a curious timeline appears. Have you missed a plot point or two or 10?