Why Keep So Many Books?

I am reading Alberto Manguel's A History of Reading. I came upon this passage that I just had to post because it speaks so well about why book lovers keep so many books:

I am once again about to move house. Around me, in the secret dust from unsuspected corners now revealed by the shifting of furniture, stand unsteady columns of books, like the wind-carved rocks of a desert landscape. As I build pile after pile of familiar volumes I wonder, as I have wondered every other time, why I keep so many books that I know I will not read again. I tell myself that, every time I get rid of a book, I find a few days later that this is precisely the book I'm looking for. I tell myself that there are no books (or very, very few) in which I have found nothing at all to interest me. I tell myself that I've brought them into my house for a reason in the first place, and that this reason may hold good again in the future. I invoke excuses of thoroughness, of scarcity, of faint scholarship. But I know that the main reason I hold onto this ever-increasing hoard is a sort of voluptuous greed. I enjoy the sight of my crowded bookshelves, full of more or less familiar names. I delight in knowing that I'm surrounded by a sort of inventory of my life, with intimations of my future. I like discovering, in almost forgotten volumes, traces of the reader I once was--scribbles, bus tickets, scraps of paper with mysterious names and numbers, the occasional date and place on the book's flyleaf which take me back to a certain cafe, a distant hotel room, a far-away summer so long ago. I could, if I had to, abandon these books of mine and begin again, somewhere else; I have done so before, several times, out of necessity. But then I have also had to acknowledge a grave, irreparable loss. I know that something dies when I give up my books, and that my memory keeps going back to them with mournful nostalgia. And now, with the years, my memory can recall less and less, and seems to me like a looted library: many of the rooms have been closed, and in the ones still open for consultation there are huge gaps on the shelves. I pull out one of the remaining books and see that several of its pages have been torn out by vandals. The more decrepit my memory becomes, the more I wish to protect this repository of what I've read, this collection of textures and voices and scents. Possessing these books has become all-important to me, because I've become jealous of the past.