Perhaps hammer and drill were a bad example. Think more of things like a ladder. Ladders are expensive and likely won't be used that frequently. You usually know ahead of time when you need it (going to wash windows on the weekend, put up Christmas lights, paint your house).

It's a fine example. I was a poor student and now I'm a minimalist. I can't imagine owning tools when I can borrow them. I've also never had a tool emergency that couldn't wait until the morning -- or maybe just a couple times in my life.

Tools aren't like a dictionary because there is no digital/online replacement for a saw.