Solopsism doesn’t really prevent anyone from experiencing or existing (or even thriving) in what we call “reality”. In and of itself, even taken to the extreme, it doesn’t necessarily seem to prevent that. There’s actually a nice little example of it in the Star Wars mythos: Daiman. There was another Sith Lord espousing similar ideas before then (Darth Ruin), but the character is largely undeveloped and there hasn’t even been a story involving him – unless you count offhand references in the Darth Plagueis novel, the Phantom Menace novel, and other such storylines.
According to Wookipedie: “The character of Darth Ruin was created by George Lucas as part of the backstory for the prequel trilogy. In Lucas’s notes, Ruin is an unnamed Jedi Knight who fell to the dark side with fifty followers 2,000 years prior to the film saga, founding the Sith. Since the Sith have been well established in other C-canon works for thousands of years, this “foundation” was degraded to be only a schism, after three previous ones. All other information on him was created by Abel G. Peña.”
Given that Ruin is, at this point in time, just an old idea that was virtually abandoned, slightly repurposed and severely downgraded in importance, then put back on the shelf, Daiman is the example I prefer to look at. This guy saw himself quite literally as the “creator of the universe”, and he tried (successfully in many cases) to instill this view in the minds of his citizens through propoganda, enforcement, torture, and humiliation… to name a few. He also sought to foster a sense that he was ever-present, always watching. Statues, morning announcements of what he has ‘decided’ would be the length of daylight on a given day, jobs in which even the most trivial writings were recovered and altered to reflect a personal variation of the alphabet, and so on.
Some of this might have hindered his efforts to maintain and expand his territory and influence, but his solopsism was just shy of being an Achilles’ Heel. His brother was someone he saw as an adversary he had created for himself to overcome, struggle was looked at as a way to solve the puzzle of a universe he had created for himself, and all of this was bolstered by the advantage of having been born into a position of power.
(Written September 21st, 2012 // Unfinished & Abandoned)