David Eagleman

An entire life, lavishly colored with agonies and ecstasies, took place in these three pounds.

In a sense, the process of becoming who you are is defined by carving back the possibilities that were already present. You become who you are not because of what grows in your brain, but because of what is removed.

In a newborn brain, neurons are relatively unconnected to one another. Over the first two to three years, the branches grow and the cells become increasingly connected. After that, the connections are pruned back, becoming fewer and stronger in adulthood.

If developing brains are not given the proper, “expected” environment – one in which a child is nurtured and looked after – the brain will struggle to develop normally.

Without an environment with emotional care and cognitive stimulation, the human brain cannot develop normally.

who we are depends heavily on where we’ve been.

But we now know that the process of building a human brain takes up to twenty-five years.

That is, in adolescence, thinking about one’s self – so-called “self evaluation” – is a high priority. In contrast, an adult brain has grown accustomed to a sense of self – like having broken in a new pair of shoes – and as a result an adult doesn’t care as much about sitting in the shop window.