This clarity made me able to behave normally, which posed some interesting questions. Was everybody seeing this stuff and acting as though they weren't? Was insanity just a matter of dropping the act? If some people didn't see these things, what was the matter with them? Were they blind or something? These questions had me unsettled.

An observer can't tell if a person is silent and still because inner life has stalled or because inner life is transfixingly busy.

As far as I could see, life demanded skills I didn't have.

Are you crazy? It's a common phrase, I know. But it means something particular to me: the tunnels, the security screens, the plastic forks, the shimmering, ever-shifting borderline that like all boundaries beckons and asks to be crossed. I do not want to cross it again.

Was everybody seeing this stuff and acting as though they weren't? Was insanity just a matter of dropping the act?

And this was the main precondition, that anything might be something else. Once I'd accepted that, it followed that I might be mad, or that someone might think me mad. How could I say for certain that I wasn't, if I couldn't say for certain that a curtain wasn't a mountain range?

Whatever we call it - mind, character, soul - we like to think we possess something that is greater than the sum of our neurons and that animates us.