This is why I love used books. My copy of Schopenhauer's collected essays has gone through 4 owners since 1914, all 4 of whom have signed and dated the front cover, all of 4 of whom have marked and underlined at different spots (including, now, myself). My copy of Riverside Chaucer went through two students before me. And they all pick up their own unique scents along the way (my girlfriend jokes that I only buy books to smell them).