The very highest states—of awe and joy, wonder and love, meaning and creativity—emerge from this bittersweet nature of reality. We experience them not because life is perfect—but because it's not.

It's not that pain equals art. It's that creativity has the power to look pain in the eye, and to decide to turn it into something better. ... The quest to transform pain into beauty is one of the great catalysts of artistic expression.

I've concluded that bittersweetness is not, as we tend to think, just a momentary feeling or event. It's also a quiet force, a way of being, a storied tradition—as dramatically overlooked as it is brimming with human potential. It's an authentic and elevating response to the problem of being alive in a deeply flawed yet stubbornly beautiful world.

The tragedy of life is linked inescapably with its splendor; you could tear civilization down and rebuild it from scratch, and the same dualities would rise again. Yet to fully inhabit these dualities—the dark as well as the light—is, paradoxically, the only way to transcend them.

This book is about the melancholic direction, which I call the "bittersweet": a tendency to states of longing, poignancy, and sorrow; an acute awareness of passing time; and a curiously piercing joy at the beauty of the world.

Today we know that the reality is far more complex. For one thing, the ARAS doesn’t turn stimulation on and off like a fire truck’s hose, flooding the entire brain at once; different parts of the brain are aroused more than others at different times. Also, high arousal levels in the brain don’t always correlate with how aroused we feel. And there are many different kinds of arousal: arousal by loud music is not the same as arousal by mortar fire, which is not the same as arousal by presiding at a meeting; you might be more sensitive to one form of stimulation than to another. It’s also too simple to say that we always seek moderate levels of arousal: excited fans at a soccer game crave hyperstimulation, while people who visit spas for relaxation treatments seek low levels.*

Extroverts are more likely to focus on what’s happening around them. It’s as if extroverts are seeing what is, while their introverted peers are asking what if.