"A child blind from birth doesn't even know he's blind until someone tells him. Even then he has only the most academic idea of what blindness is; only the formerly sighted have a real grip on the thing. Ben Hanscom had no sense of being lonely because he had never been anything but. If the condition had been new, or more localized, he might have understood, but loneliness both encompassed his life and overreached it."

Source: Stephen King (2016). “It”, p.190, Simon and Schuster