Claude Monet disliked being cooped up inside. Growing up in the French port city of Le Havre, he would often skip school to roam the beaches along the Normandy coast. Or he would wander the docks, listening to the workers speak in foreign languages as they unloaded cargo ships. The outdoors felt like his natural habitat.

“School was always like a prison to me,” Claude later recalled. “I could never bring myself to stay there when the sun was shining and the sea was so tempting, and it was such fun scrambling over cliffs and paddling in the shallows.”

Claude inherited his love of nature from his mother, Louise-Justine Aubrée Monet, a refined and elegant woman who liked to paint and write poetry. She used to carry around a pocket-sized sketchbook all the time, the better to record her impressions of the town and its inhabitants.

By contrast, Claude’s father spent most of his time indoors. Claude-Adolphe Monet was a grocer by trade. He preferred that his second son follow him into the family business, but Claude didn’t want that job. From an early age, he set his sights on becoming an artist.

At school, Claude was drilled in Latin and Greek, reading and arithmetic. He also took an art class with a French painter named François-Charles Ochard, who tried to teach him how to draw figures in the classical style. But Claude was far too independent-minded to follow Ochard’s instruction. “I was born undisciplined,” he later said. “Never, even as a child, could I be made to obey a set rule. What little I know I learned at home.”

Instead of copying figures out of textbooks, Claude liked to doodle in the margins. He filled page after page with sketches of sailing ships and funny portraits of his teachers. “I drew the faces and profiles of my schoolmasters as outrageously as I could,” he said, “distorting them out of all recognition.” At family picnics, Claude would hand out sketchbooks to relatives and challenge them to a drawing contest. He always won.

A family friend named Théophile Beguin-Billecocq encouraged Claude by buying some of his pictures. “His sketches, whether in crayon or pencil, were always excellent,” Billecocq wrote in his journal. “He knew how to capture the essential characteristics of a scene.”

Before long, Claude became well known in his town for his amusing caricature sketches. Passersby would ask him to draw their picture and pay him ten francs a sketch. Within a month, the young artist’s clientele had doubled—and so had his fee. “Had I gone on like that I’d be a millionaire today,” he later said.

The owner of the local art supply store started hanging Claude’s pictures in his shop window. Each week, a new one would appear. Soon there were five or six of Claude’s caricatures lined up in a row, each one in its own golden frame, like a work of fine art. Claude swelled with pride every time one of his neighbors walked by and recognized the person portrayed in his pictures.

One day the shop owner introduced Claude to a man who would change his life forever. Eugène Boudin was a local landscape painter who liked to work outdoors, or en plein air, as the French would say. Boudin liked to paint beach scenes and images of ships moored in the harbor. He had seen some of Claude’s drawings and thought he had potential to be a painter, too.

“I always look at your sketches with much pleasure,” Boudin told him. “They are amusing, clever, and bright. You are gifted. One can see that at a glance. But I hope you are not going to stop at that. It is all very well for a beginning, but soon you will have enough of caricaturing.”

Boudin invited Claude to paint with him in the open air. “Study, learn to see and to paint, draw, make landscapes. They are so beautiful, the sea and the sky, the animals, the people and the trees, just as nature has made them, with their character, their true existence in the light and the air, just as they really are.”

At first, Claude declined Boudin’s invitation. Though he loved the outdoors, he had never painted nature scenes. Besides, his caricatures already sold for far more money than Boudin’s landscapes ever did.

Over the next several months, Boudin repeated his offer, but Claude always came up with a reason not to accompany him on his jaunts in the countryside. Finally, summer came, and with it the end of the school year. Claude had plenty of free time and had officially run out of excuses not to join Boudin. Besides, the weather was so nice that the idea of spending some time outside was starting to appeal to him.

So one day Claude gave in and went on an outdoor painting excursion with Boudin. Together they headed out to the coast, near the mouth of the Seine River.

Claude watched with fascination as Boudin daubed his canvas and began to paint the things he saw: the sandy beach, the open sky, the puffy clouds, the sunshine as it dappled the water. Looking on, Claude was overcome by a deep emotion. “I was enlightened,” he said later. “It was as if a veil had been torn aside. I had grasped what painting could be.”

Inspired by Boudin’s example, Claude worked feverishly on his own canvas. It wasn’t as good as Boudin’s, but it was a start. Claude had found a new inspiration. “My way was clear, my destiny decreed,” he said. “I would be a painter, come what may.”

By this time, Claude was living with his aunt in Paris. While there he noticed many young painters copying the works of the old masters, just as he had done back in Monsieur Ochard’s class. But thanks to his friend Boudin, Claude had found another path to making art. He spent his days standing by an open window painting what he saw.

Claude spent the next several years in Paris. He befriended many of the artists who would later join him in founding what became known as the Impressionist movement. Along with artists like Edouard Manet, Pierre-Auguste Renoir, and Paul Cézanne, Claude Monet went on to change the face of art forever. But he never forgot where it all began. If he had achieved any fame as an artist, he once admitted, “It is to Eugène Boudin that I owe the fact.”