The eye-catching posters were everywhere during my recent visit to London: Katsushika Hokusai’s “Beyond the Great Wave” was the major spring exhibit at the British Museum. Maybe I should go, I thought. But I had no idea that this Japanese master of woodblock art and the stunning work of his final 30 years at the heart of the show would affect me so deeply.

The “Thirty-Six Views of Mt. Fuji” series was completed when Hokusai was 71, midway through his long career. He himself commented when those works were finished, “until the age of 70, nothing I drew was worth notice.” Each of the 36 woodcuts shows a unique perspective on only one thing, Mt. Fuji. Regarding the mountain, in its regularity and symmetry, as a symbol of immortality, Hokusai spent more than two years on his project of the 36 views.

In one of them, Under the Wave off Kanagawa, he shows Mt. Fuji as a calm, fixed point in the distance, behind the dramatic action occurring in the foreground. Right in front of us, a giant wave curls over three small fishing boats whose oarsmen row frantically to escape disaster. We hold our collective breaths, fearing for the men in the boats. But as spectators, we also see that as the wave crests, its droplets become gentle rain, or possibly flakes of snow, falling through still air onto the top of the mountain.

In other prints in the series, Hokusai captures Fuji on a Clear Day with a Southern Breeze (which he called “Red Fuji”), from the point of view of men fishing on the shore of a lake, and from revelers in a garden, with one of their kites towering over a far-away, miniature Mt. Fuji. The artist’s commitment to these multiple perspectives is remarkable. Being so preoccupied with a single focus is hard to imagine, but Hokusai’s dedication results in portraits of Japanese life that intrigue and inspire.

Hokusai worked zealously until the day he died, at nearly 90. As an onlooker in a darkened museum, I traveled with him through his old age, contemplating an imagination that became more intense and vivid as time went on, and on. His large, red Shoki the Demon-Queller suggests a source of power in the face of life’s perils. A spectral illustration from One Hundred Ghost Tales, with its claw-like hands and teeth hanging around its neck like a set of beads, is both humorous and haunting. Visions of my own ghosts darted across my mind as I stood in front of it.

Until now, Hokusai had been only vaguely familiar, an early 19th century artist who concentrated on scenes and story illustrations from a country I’ve explored only briefly, on a stopover in Tokyo. The length of time I spent in Japan was about equal to the level of my interest in most things Japanese, with the exception, as a writer, of enjoying the form of haiku.

At the end of the exhibit, I bought a few postcards of the Mt. Fuji prints and also of the dragons, animals, flowers and eerie figures that came after them. I know they will have more to say to me as time goes on.

Through a single encounter during a brief afternoon at the British Museum, Hokusai became an influential presence in my life. I am moved by his art, but even more by his insistence on old age being a period of unique and enjoyable creativity, because of being old. After finishing The Great Wave, Hokusai incorporated a statement of his age into his signature for every additional piece he completed. It was a matter of pride.

For Hokusai, old men released their powers through the force of their art. With the brilliance of his own work during those long final years, this Japanese printmaker advocates perseverance, perspective and passion. He urges me, being also over 70, to value these traits too.

As I walked out of the museum, I remembered one other significant encounter I had had with something Japanese, the Buddhist “Evening Gatha.” I listened to it each night during a haiku writing workshop at a Zen monastery: “Let me respectfully remind you …. Time passes swiftly by and opportunity is lost. Do not squander your life.”

Had Hokusai heard these words too?

Mary Otto lives in Norwich.