To the author's point, yes I remember the main themes/movements in the Steinbeck books I have read. I remember them for the Dostoevsky and Tolstoy I have read. I remember them for most good books I have read, even if the reading happened in high school, or 10+ years ago. Good books are almost like a lived-experience. Yes, they are not as "creative" as sketching, or writing an essay, but reading can also require creativity on the part of the reader.