You can't say 'if this didn't happen then that would have happened' because you don't know everything that might have happened. You might think something'd be good, but for all you know it could have turned out horrible. You can't say 'If only I'd…' because you could be wishing for anything. The point is, you'll never know. You've gone past. So there's no use thinking about it.

Lords And Ladies: (Discworld Novel 14) (ed. Random House, 2008) - ISBN: 9781407034874