From the man himself: "It is foolish to think that you have to read all the books you buy, as it is foolish to criticize those who buy more books than they will ever be able to read. It would be like saying that you should use all the cutlery or glasses or screwdrivers or drill bits you bought before buying new ones.
There are things in life that we need to always have plenty of supplies, even if we will only use a small portion. If, for example, we consider books as medicine, we understand that it is good to have many at home rather than a few: when you want to feel better, then you go to the 'medicine closet' and choose a book. Not a random one, but the right book for that moment. That's why you should always have a nutrition choice!
Those who buy only one book, read only that one and then get rid of it. They simply apply the consumer mentality to books, that is, they consider them a consumer product, a good. Those who love books know that a book is anything but a commodity." – Umberto Eco