[bscphil]

Fair enough, I do need to have a look at the book again, although that was one of the sources I found impossible to understand a few years back. I think there's a temptation to talk about lifetimes in extremely abstract terms under the assumption that the reader already understands and appreciates the abstraction. I, however, was never able to build up an intuition for it, and so tutorials that didn't explain what was happening in detail sailed over my head.