"Naturally, any addicted reader's greatest pleasure is to discover some new book or author - unexpected, sympathetic, in tune with one's mood. But there are also times when an old favourite will do, something one can rely on for enthralled contentment. To qualify as an absolutely prime old favourite a book needs partcular qualities. It must be capacious enough to immerse the reader completely. The characters must be like old acquaintances, familiar but never absolutely understood, and the events must become almost one's own memories. The best of such books are always fresh because, as one grows older, they provide new insights and amusements in the light of one's wider experience of self and others."
Perhaps this is one reason that books read as a child, when the boundary is still so amorphous between self and world, between reality and imagination, stay with us, influence us and are so dear to our hearts. They have become "one's own memories."