If someone writes a memoir well enough, that person ceases to feel like a stranger at all, particularly when something she has written finds you at exactly the moment when you need it, so that it seems this writer is speaking directly to your soul.
Take, for example, Amy Fusselman's 8, a scorcher of a book. For me, reading this passage at a confused and confusing time just about took the top of my head off:
"Time is inside and outside us, it is the fantastic sea we move through, capable of the most astonishing bends and whorls and, of course, like most things that are magical and wild and inside us, we have reduced it to something small and controllable outside us. Time is not magical, we say. Time is the annoying thing I wear on my wrist."
She had no way of knowing I was battling impatience, struggling with parenting—its difficulties, its roboticness—when she reminded me of the beauty and magic of it. But still, this stranger, who was kind enough to tell her story, made me a better parent, and probably a better person.