Katsushika Hokusai started learning to draw when he was about 6 years old, copying the world around him. By his teens he was carving wooden printing blocks in a Tokyo workshop. He kept changing his name, his subjects, and his style for the rest of his very long life.
His most famous picture is a colorful woodblock print called The Great Wave off Kanagawa. It shows a huge curling wave with little white claws of foam reaching toward three tiny boats - and Mount Fuji peeking up in the background looking almost calm by comparison. He was around 70 when he made it.
Hokusai never thought he was done improving. In his old age he said that nothing he had drawn before age 70 was worth looking at, and that if he could live to be 100 or older, he might finally know how to make a real line. He died at 88, complaining that he just needed five more years.