From Diaspora (1997) by Greg Egan:
[…] He turned to Paolo, his expression suddenly, painfully naked. ”I know I’m not flesh and blood. I know I’m software like everyone else. But I still half believe that if anything happened to the polis, I’d be able to walk out of the wreckage into the real world. Because I’ve kept faith with it. Because I still live by its rules.” He glanced down and examined an upturned palm. ”In the macrosphere, that will all be gone. Outside will be a world beyond understanding. And inside, I’ll just be one more solipsist, cocooned in delusions.” He looked up and said plainly, “I’m afraid.” He searched Paolo’s face defiantly, as if daring him to claim that a journey through the macrosphere would be no different from a walk through an exotic scape. “But I can’t stay behind. I have to be a part of this.”