"I'd have noticed, if it were them"

Here's the objection that keeps the audience alive after the last four chapters. Fine, people don't notice much. But I do. I notice the person who trips, the person eating alone, the coat that doesn't go. I'm a watcher. So the room is full of people like me, and they're watching.

Erica Boothby, Margaret Clark and John Bargh published six studies in 2017 on this exact belief, and gave it a name, the invisibility cloak illusion. People believe that they observe others more than others observe them. They believe it about strangers in the same room and about friends they're talking to. It's not the general sense most people have of being a bit better than average at things, because the authors checked for that, and it isn't explained by believing you simply have more thoughts than other people. It's specific. Everyone thinks they're the watcher.

The authors make the point that has to be made. On average, that can't be true. Every act of watching has a person being watched, and if every person in the room believes they're doing more watching than being watched, most of them are wrong. Which is you, most of the time. You are watched about as much as you watch, which chapter 3 suggests isn't much, and you believe you're watched less than that, which is what the cloak means, and the belief holds even when they made people focus on a feature of their own appearance. That last result matters for the mark and comes back in chapter 9.

Now turn the objection round, because it does something useful. You're right that you notice the person who trips. What did you do with it? Try to recall, honestly, the last stranger you saw trip, or eat alone, or wear something that didn't go. Recall their face. Recall what you concluded about them as a person and how long you held it. If you're like the people in these studies, you noticed, had a half-thought, and were back inside your own head within a few seconds, and you don't have the face. That's what you're doing to them. It's what they're doing to you. Chapter 20 turns this into a method.