Anxiety is the unpleasant emotion that's characterized as a state of high mental arousal. Calm is the polar opposite of that, and we tend to live in this state: low mental arousal. That's why I have the onyx books instead of looking at my phone or my iPad at night. Could I do this stuff on those devices? Yeah, but I don't even want the possibility. So I'm building stronger barriers there to keep my brain on track.