Sam frowned and shrugged. 'All of it. Why?'

Thomas fished one of his pens out of his blazer pocket. 'Don't look,' he said, 'just keep staring at the road and try to tell me what color my pen is.' He held it up in her periphery: a Bic made in India.

Sam smiled, staring with corner-of-her-eye concentration. 'It is tough,' she said, 'but I'm pretty sure it's blue… Yep. It's blue. It's gotta be.'

Thomas handed it to her. It was bright red.

'We actually live in a primarily black and white world, with a narrow ring of color immediately before us. Our brain fills in the rest.' He spent several minutes explaining how the discovery of things like inattentional blindness, change blindness, masking, perceptual asynchrony, processing lags, and so on had overturned millennia of speculation in just two decades. 'You could make a career out of cataloguing all the ways in which consciousness is either blinkered or outright deceptive,' he said. 'The gap between the environmental information we think we take in, and the actual information we have access to is nothing short of staggering. It's so bad that most cognitive scientists refer to the experience you're having now—your sensorium as they like to call it—as the "Grand Illusion".'

Just then an eighteen-wheeler pulled onto the road a short distance ahead, forcing Sam to break to a crawl. Dust rolled over the car. 'If it's as bad as all that,' she asked, obviously irritated, 'then why doesn't it seem that way?'

'But how could it seem otherwise? It's the only frame of reference you have.'

He could tell from her gaze that she wasn't so much watching the eighteen-wheeler's towering rump as she was watching herself watching it. He could remember his own reaction to these facts in his freshman psychology class. He'd always been a reflective kid, but for the first time he found himself staring at his experience rather than the things within it. He could remember probing his visual field in particular, trying to understand how it could simply 'run out' without having any visible edge. Everything suddenly seemed at once fictional and impossible, like paint splashed across something monstrous. And quick, terrifyingly quick. Psychologists called such episodes 'derealization'. The irony was that they used the term to describe a kind of disorder, when it was about as accurate as any conscious experience could get.

It had certainly freaked him out—so much so he had sworn off dope for three months.

'Consciousness is an end-user,' Thomas continued, 'and a poor one at that. Out of all the information our brains crunch every second, only a tiny sliver makes it to conscious experience—less than a millionth, by some estimates.'