" Reading, for all of us, is fettered only by obvious restrictions. You can't own all that you want or need to read. There are, then, two kinds of books--yours, and the contents of libraries. There is the actual, personal library, your own shelves, which mark out reading inclinations, decade by decade, and the virtual library in the head--the floating assemblage of fragments and images and impressions and information half-remembered that forms the climate of the mind, the distillation of reading experiences that makes each of us what we are. "

― Penelope Lively , Dancing Fish and Ammonites: A Memoir