My walking companion, John Pepper, was diagnosed with Parkinson’s disease, a movement disorder, over two decades ago. He first started getting symptoms nearly fifty years ago. But unless you are a perceptive and well-trained observer, you would never know it. Pepper moves too quickly for a Parkinson’s patient. He doesn’t appear to have the classic symptoms: no shuffling gait; no visible tremor when he pauses or when he moves; he does not appear especially rigid, and seems able to initiate new movements fairly quickly; he has a good sense of balance. He even swings his arms as he walks. He shows none of the slowed movements that are the hallmark of Parkinson’s. He hasn’t been on anti-Parkinson’s medication for nine years, since he was sixty-eight years old, yet appears to walk perfectly normally.

In fact, when he gets going at his normal walking speed, I can’t keep up with him. He’s now going on seventy-seven and has had this illness, which is defined as an incurable, chronic, progressive neurodegenerative disorder, since his thirties. But instead of degenerating, John Pepper has been able to reverse the major symptoms, the ones that Parkinson’s patients dread most, those that lead to immobility. He’s done so with an exercise program he devised and with a special kind of concentration.

The beach we are on is called Boulders because of the huge, round rocks that ring it, lined up like adjacent marbles. It is just off the southernmost tip of Africa, where the Indian and Atlantic Oceans meet, and we have come to observe an African penguin colony. Slightly off the beaten path, we are in search of jackass penguins, so known because of their braying mating calls. We see our first penguin as it rockets out of the Indian Ocean with optimistic grace. It’s called porpoising. But when the penguin comes ashore, he has an ungainly waddle.

We have been told that in the next little stretch of sand, which is surrounded by the huge ten-foot-tall boulders, we will find a group of penguins and their babies. But I don’t see how we will reach them through the wall of rock because the cracks between the boulders are so narrow and low.

The Brain's Way of Healing: Remarkable Discoveries and Recoveries from the Frontiers of Neuroplasticity