Just before she flew off like a swan to her wealthy parents' summer home, Bruce's college girlfriend asked him to improve his expertise at oral sex, and offered him some technical advice:

Use nothing but his tonguetip to flick the light switch in his room on and off a hundred times a day until he grew fluent at the nuances of force and latitude.

Imagine him at practice every evening, more inspired than he ever was at algebra, beads of sweat sprouting on his brow, thinking, thirty-seven, thirty-eight, seeing, in the tunnel vision of his mind's eye, the quadratic equation of her climax yield to the logic of his simple math.

Maybe he unscrewed the bulb from his apartment ceiling so that passersby would not believe a giant firefly was pulsing its electric abdomen in 13 B.

Maybe, as he stood two inches from the wall, in darkness, fogging the old plaster with his breath, he visualized the future as a mansion standing on the shore that he was rowing to with his tongue's exhausted oar.

Of course, the girlfriend dumped him: met someone, aprËs-ski, who, using nothing but his nose could identify the vintage of a Cabernet.

Sometimes we are asked to get good at something we have no talent for, or we excel at something we will never have the opportunity to prove.

Often we ask ourselves to make absolute sense out of what just happens, and in this way, what we are practicing

is suffering, which everybody practices, but strangely few of us grow graceful in.

The climaxes of suffering are complex, costly, beautiful, but secret. Bruce never played the light switch again.

So the avenues we walk down, full of bodies wearing faces, are full of hidden talent: enough to make pianos moan, sidewalks split, streetlights deliriously flicker.

• from the book Donkey Gospel. Read it!