The idea that we can cultivate the soul or the self like a garden goes back to ancient times and is beginning to be applied to the brain in contemporary science. It is, of course, replacing one metaphor with another but we cannot think in any sophisticated way without metaphors. Furthermore, this one is more accurate. The cells that create our neural networks grow in the form of tree-like branching structures and were originally named dendrites after the Latin word for tree because of their visual similarity to one. This resemblance, it has recently been discovered, reflects the fact that neuronal arbours and plants grow according to the operation of the same three mathematical laws. A deeper similarity can be found in the active process of pruning and weeding that maintains the health of our neural networks and is carried out by a group of cells which function as the brain's resident gardeners.

A director of a play has a peculiar job. For weeks, she orchestrates every move made by various people in a variety of roles, from actors to support personnel. Little happens without her intervention in one way or another. When the play opens, however, the director is essentially useless. If the cast and crew still need her, she is a failure. Teaching is, or at least ought to be, like that. Every day, the teacher should make himself increasingly useless in his students' lives. These kinds of teachers do not provide solutions when students can figure things out for themselves. They provide directions and guidelines for quality, but they leave some ambiguity, choice, and flexibility so that students have to make leaps of transfer and apply common sense. They take careful measure of how much responsibility children can manage, making sure to give them that much - and coaching for a bit more as well.

Strengths are contextual. Any personal quality can be either an aptitude or a handicap, depending on the situation. Let's say you have difficulty reading printed text. This might understandably seem like a shortcoming, especially if you want to be a literary critic, a profession heavily dependent on the parsing of texts. But if you want to be an astronomer, the same apparent shortcoming could turn into an unexpected strength. The brains of many people who have trouble reading are better at detecting black holes and other celestial anomalies in astronomical images than the brains of individuals without reading difficulties. A facility for empathy is an asset for a nurse, but a shortcoming for a military drone pilot. Being tall is an advantage for an NBA player, but a disadvantage for a coal miner.