Knowing yourself now requires the understanding that the conscious you occupies only a small room in the mansion of the brain, and that it has little control over the reality constructed for you.

When a male vole repeatedly mates with a female, a hormone called vasopressin is released in his brain. The vasopressin binds to receptors in a part of the brain called the nucleus accumbens, and the binding mediates a pleasurable feeling that becomes associated with that female. This locks in the monogamy, which is known as pair-bonding. If you block this hormone, the pair-bonding goes away.

The three-pound organ in your skull - with its pink consistency of Jell-o - is an alien kind of computational material. It is composed of miniaturized, self-configuring parts, and it vastly outstrips anything we've dreamt of building.

When we're in a human body, we don't care about universal collapse - instead, we care only about a meeting of the eyes, a glimpse of bare flesh, the caressing tones of a loved voice, joy, love, light, the orientation of a house plant, the shade of a paint stroke, the arrangement of hair.

Just like a good drama, the human brain runs on conflict.

If choices and decisions derive from hidden mental processes, then free choice is either an illusion or, at minimum, more tightly constrained than previously considered.

There are always wonderful mysteries to confront.