You can always return them to the bank after you use them. I've got a friend who looks for rare coins this way - he takes out $100 of coins from the bank at a time, looks through them all, keeps a few, and returns the rest, and then tries again.

Or maybe just wanting to know more about a subject doesn't mean that you don't know anything about it. I'm studying for my Ph.D. in math, and I still voted for Pure Math.

And so when I start up Firefox, hoping to start browsing, I first have to think about whether I want to update it. I almost always click "Don't update" (with my add-ons also) because I just don't feel like waiting for it to update and restart. And of course, I never think about updating when I'm not browsing (why should I think about Firefox when I'm doing something else)? So Firefox rarely gets updated for me, which can't be a good thing. I'd much rather it just do it in the background and not tell me about it.

This is a bit extreme. While they're certainly not the best books to begin learning a subject, they're great reference books. They're well written, (generally) correct, and what's more, they've got some seriously elegant proofs. And from what I recall, they do have some diagrams (e.g., their commutative algebra book).