Are repressed memories real? A hit memoir clashes with the science.

What if something terrible happened to you, and you weren’t able to remember it? That’s one of the questions at the center of Amy Griffin’s memoir, The Tell, which is quickly becoming one of the year’s most talked-about books.

Griffin’s buzzy bestseller doesn’t offer easy answers or tidy conclusions about its dark subject matter — its author’s sexual assault by a trusted teacher as a preteen — which only seems to make her story about recovering harrowing memories of the abuse after trying...