The fifty-third Chuang Tzu wore the very first on his cloak as a diamond buckle. Every emperor became a diamond eventually. It was one of the few adv… - Jon Courtenay Grimwood

Apparently this was a design flaw in the unaugmented human brain, a lagging of consciousness behind intent.

Why would we do this? she asked, watching smoke trickle towards the ceiling. A whole world of rigid rules covering temperature, convection and Brownian motion all busily pretending to be truly chaotic.

The third nightfall was less impressive than the second, which mirrored a rule Tris had already identified; new emotions devalued, going from intense through familiar to reach a kind of ghost state where one no longer really noticed them at all.