We know Mustapha to be a philosophical man, the one knows the reasons why the BNW is, for the greater part, brave. It's interesting to me how I can't find out if he's a humble man or not. My reading his dialogue in the exposition and his confrontation with John the savage isn't enough to make me so sure yet.
So, we don't actually know how Mustapha Mond got the job of Controller. I don't think that in huxley's BNW, he had the chance to choose what he did with his time, maybe he had to be like the Giver (anyone read Lois Lowry?).
But let's just say that if there was a way that he could come into governing the entire World State the way it was goverened in the book,
....what would be in it for him? I'd like to start up a conversation with anybody at all!