I'm not going to rely on a long retirement. I lost two relatives a couple of years ago; one was 100, and one was 67. How can I possibly make a guess at how much retirement I'll have, if any?
If I'm totally honest, I buy more books because buying books is as much of a hobby as reading them. I even hang out on forums to chat about buying them.
I went a bit mad for a couple of years, and binged on freebies and bargains, but I'm glutted now, and only pick up things I actually want. I am still subject to sudden enthusiasms, which make me seek out and maybe buy lists of books, but I'm hoping I can make some progress on my last batch before it happens again.
The important thing is that I have enough choice to pick something to read next that suits my mood.