Thinking about opening lines

Further to the post yesterday, about the unrecognised (or was it) lightly disguised Jane Austen mss affair.

a) If, as various people allege in comments, this happens to publishers all the time, people sending them great works of classic literature, or even non-classic literature, very lightly adapted or even with just the names changed, why did none of the editors and agents actually say 'This happens all the time, and our policy is to take no notice and just send a form letter'? Instead of saying, as reported (which of course may be v selective), things which just sounded like muddled and implausible excuses for employing people who could not spot one of the most well-known opening lines in the whole of EngLit.

Which led me on to thought b) which was, this is one, but there are other, examples of opening lines which have become classics in their own right, and thus (perhaps?) detached in people's minds from the actual book which they open.

E.g. 'It was the best of times, it was the worst of times'; 'Call me Ishmael'; 'The past is another country: they do things differently there'. (I would have guessed that the latter was maybe a great deal more cited than The Go-Between read, these days, but I see that it is in print and that there are various Brodies etc Notes, so maybe it has achieved setbook status while I wasn't looking).

What other first lines have entered the popular consciousness in this way?