Just Kids is a memoir written by the musician and poet Patti Smith, focusing on her relationship with the photographer Robert Mapplethorpe, from their first meeting in 1967, when they were both twenty, to Mapplethorpe's death from AIDS in 1989 at the age of forty-two.

The foreword begins with Mapplethorpe's death, which occurred while the author was at home, asleep with her husband and family. After a very brief description of her reaction to his death, Smith returns to her early youth for the beginning of the first chapter. She writes about her childhood in Chicago and in Germantown, Pennsylvania. Two of the most important milestones in her childhood were learning to pray and learning to read (which her mother taught her after she discovered that Smith had been trying to absorb the meanings of books by putting them under her pillow before she slept). Smith also describes visits to her friend Stephanie, who had leukemia. She was fascinated by Stephanie's possessions and once stole a pin from her jewelry box. The next day she was ill and vowed to return the pin as soon as possible. Stephanie died the next day, however, and Smith had contracted scarlet fever, so she could not even attend her funeral.

Smith describes her childhood literary and musical influences and her ambitions to be an artist. Her first serious argument with her father was about Picasso, whose work he did not admire. Smith herself loved Picasso and was drawn to the work of artists as different as Fra Angelico and Modigliani. In the summer of 1966, Smith slept with a boy of seventeen and quickly became pregnant. She found a family willing to adopt the baby and, soon after giving birth, took a bus to New York City to make a fresh start. She soon met Robert Mapplethorpe, who came into the bookstore where she worked and later helped her to get out of an awkward date with an older man by pretending to be her boyfriend.

Both Smith and Mapplethorpe were very poor, but after weeks of living with friends, they managed to rent an apartment together at 160 Hall Street in Brooklyn for $80 a month. Smith describes how they furnished their home with objects scavenged from the streets and given to them by friends. Although they were not materialistic in the conventional sense (i.e., caring for objects that cost a lot of money as a display of material wealth), they both cared greatly about their physical environment, the objects with which they surrounded themselves, and their clothes, which they regarded as a type of performative art. One of their first memories together was of their mutual admiration for a Persian necklace which Smith had coveted and Mapplethorpe bought.

At first, Smith and Mapplethorpe spent all their time together in the apartment, never leaving each other's side except to go to work, or at all when they lost their jobs. They worked on their artistic projects in parallel, supporting and encouraging one another with the similarity of their artistic visions and aspirations. Smith wrote poetry, while Mapplethorpe made collages and sculptures of found objects.

As early as the summer of 1968, however, Smith and Mapplethorpe began to grow apart. Although their relationship lasted for more than twenty years, after the first year, in which they were lovers living together, the nature of that relationship defied conventional categories. By the time Mapplethorpe died, Smith was married with children, while Mapplethorpe was gay. In 1968, Smith left the apartment she shared with Mapplethorpe and began a relationship with the painter Howard Michaels. Mapplethorpe moved...