While it can certainly be seen either way, I believe it's real. When he talks to his coworker about doing the virtual vacation, and he tries to talk him out of it, the coworker has a look of concern on his face. Not so much one that says "This guy needs help" or "I couldn't care less about your shitty life", but "Oh shit, this could end badly if his old memories come back". And there seem to be other subtle clues throughout that point to it being all real, even if he may doubt it.