I'm going to be late for work. Again!
Rincewind: I do not wish to volunteer for this mission.
Lord Vetinari: I beg your pardon?
Rincewind: I do not wish to volunteer, sir.
Vetinari: No one was asking you to.
Rincewind: Oh, but they will, sir, they will. Someone will say: 'hey, that Rincewind fella, he's the adventurous sort, he knows the Horde, Cohen seems to like him, he knows all there is to know about cruel and unusual geography, he'd be just the job for something like this.' And then I'll run away, and probably hide in a crate somewhere that'll be loaded on to the flying machine in any case.
Vetinari: Will you?
Rincewind: Probably, sir. Or there'll be a whole string of accidents that end up causing the same thing. Trust me, sir. I know how my life works. So I thought I'd better cut through the whole tedious business and come along and tell you I don't wish to volunteer.
Vetinari: I think you've left out a logical step somewhere.
Rincewind: No, sir. It's very simple. I'm volunteering. I just don't wish to. But, after all, when did that ever have anything to do with anything?
Ridcully: He's got a point, you know. He seems to come back from all sorts of-
Rincewind: You see? I've been living my life a long time. I know how it works.