Mark O'Brien was an American poet and essayist known for his unique perspective on life and disability. Born in 1952, he contracted polio at a young age, which left him with significant physical limitations. Despite these challenges, O'Brien pursued his passion for writing and earned a degree from the University of California, Berkeley. O'Brien's work often explored themes of love, desire, and the human experience. He gained wider recognition through his essay "On the Sidewalk," which was later adapted into the film The Sessions, highlighting his journey and relationships. His contributions continue to inspire many in the literary world.