Fiction by Marilynne Robinson.
This is the story of a girl who grew up homeless before and during the Depression era (back when people weren't called "homeless," but rather "hobos" or "bums") with a woman who loved her but wasn't her mother. With this upbringing, Lila is almost a wild thing, having never really been tamed to live indoors. One day, however, loneliness drives her to tie herself to a life in a house.
Intertwined with the story of Lila are a lot of unanswerable questions about human suffering and isolation. This is not a light story, although it is a short book. It gives you something to think about.