Imperial Dream: Ah, yes, the Imperial Dream. Eudaimonia, or the “exercise of vital powers, along lines of excellence, in a life according them scope” as Aristotle put it. Which scope, it is generally said, is afforded by the Empire being a place where – to steal a perfectly good quotation from Bioshock – “a man is entitled to the sweat of his brow, the artist does not fear the censor, the scientist is not bound by petty morality, the great are not constrained by the small”, etc., etc., there are limitless possibilities and opportunities for anyone with the wit to seize them or make them, and everyone is unbound to pursue their personal growth, prosperity, and general awesomeness without having the rest of the crabs in the bucket drag them down. Success may not be guaranteed, but everyone will get out of your way and let you try.
(This is for values of “petty morality” equal to “small-minded parochialism and choice-stealing dogooderism” and small equal to “the envious, the power-hungry, petty jobsworths, the fearful and cowardly, Luddites, regressives, and other fluffers of regress and relative status hierarchies”, of course.)
Depending on the exact point of view of the person having it, may also have elements in common with the American Dream, the Former Galactic Empire Dream (‘richness, wildness, no taxes”), and the Ankh-Morporkian Dream (“making boatloads of cash in a place where your death was not likely to be a matter of public policy”).
Cynics, of course, point out the dark side. The Empire is a wonderful place if you happen to be the right sort of ambitious, self-motivated, self-defining, run-through-life-without-a-guidebook, make-it-up-as-you-go-along soph, because that’s who it was built by and for. On the other hand, if you don’t fit that category, and/or need a bunch of expectations and norms and rules and conformity to define yourself by, going there is treating yourself to an anomic hell which will run you right over and into the ground, and almost certainly not even notice that it’s doing it.