I borrow books from our library a lot. I pay fines when I am late, and have on occasion had to pay to replace a lost or damaged book. I purchase my own books too, but I rely heavily on the library for supplementation to my private book collection.
Sometimes I borrow books from friends. I work hard to keep track of them and take care of them. I think I have returned them all. But I have loaned a lot of books to other people that I never got back. I have become a bit more selective about what books I am willing to loan out. I tend to loan fiction more frequently. I don't like to loan books that were difficult to purchase or expensive to replace. (My definition of expensive is pretty low. I buy most of my books second hand.) My favorite nonfiction books tend to get opened often, so I don't really like to loan those. But overall, that still leaves a lot of books that I am willing to loan out.
The borrowing and loaning of books is an old practice. Abraham Lincoln would walk miles to borrow books from neighbors. Benjamin Franklin founded America's first lending library. Books used to be quite expensive, which encouraged lending through libraries and throughout communities. Even though books are less expensive now, libraries continue to be an excellent resource for many books.