Gordon Parks, the great American photographer/filmmaker found his calling in 1947 as a conductor on a train; not as a conductor but as a photographer. Someone left a magazine on a train seat with a photographic spread detailing a social issue of the day. Parks believed that the images held a power to tell a story and possibly change the world. So, when his train arrived in Seattle, he bought a camera for $7 and commenced a career in the visual arts that took him to the pages of Look and Life magazine, among others. He had an incredible compositional eye as well as an eye for light and shadow. He was sent on assignment once to document the life of a low-income family in Harlem, and on another occasion with a similar family in a Brazilian favela. In the 60s he became friends with Malcolm X and documented his work; in the late 60s he spent time with the Black Panthers also photographing their lives. His later career dipped into film directing, most notably with the film Shaft.
His whole life developed a trajectory from his chance encounter with a magazine photo spread. It's important that we stay awake to ideas and opportunities that may present themselves to us—a random event may send us on a positive life journey.