 more than anything else. You can only consciously think about one or two things at a time. That's it. This is a fundamental limitation of the human brain. The human brain has not changed significantly in 40,000 years. It ain't going to change on any time scale. We're going to see. But the average teenager now believes they can follow seven forms of media at the same time. So people like Professor Miller, they get people into labs, not just kids, older people too, and get them to think they're doing more than one thing at a time. And what they discover is always the same.