Of course, he won't really retire - there'd be no books for us to read then. But when did it become such an integral aspect of his character to most that he was so driven he never could retire?

I recall some people hating that in The Dark Knight Rises he retired, saying it was antithetical to his character and that he'd stay Batman until he died on the job. I didn't care for the movie either, but that wasn't my primary problem. But it did lead me to think about when that became a thing to so many people (I've certainly seen it enough, anyway). In early comics, retirement was a given. To a degree it makes sense - Bruce was less obsessed in those days (determined and driven, but not to the exclusion of so much else in his life). And at a certain point, the body just can't do what it used to (look at typical age of retirement for athletes). Early on, I think he though he'd complete his mission (making Gotham significantly better, if not perfect), or maybe (after Robin) hand it off to someone he trusted.

Anyway, I would just assume the change came with COIE, but in early Robin issue, he again expresses he notion that he thought he could retire (when Jean-Paul Valley took over). So is that because that aspect of Bruce's personality hadn't been introduced yet, or had it been introduced, but not solidified and pre-COIE Bruce was still leaking in or somewhat there?