Barbara Kingsolver's The Bean Trees introduces us to Marietta, who now goes by Taylor, a young woman seeking adventure. Taylor comes upon parenting on accident when a baby is forced upon her by a desperate woman at a gas station. Taylor has a supply of t-shirts, and the "Damn, I'm Good," shirt is too small, making it the best option for the baby to wear.
The slogan references the pride Taylor is taking in caring for Turtle, Taylor's hope that Turtle might be her ticket into a Native American Reserve, and, ironically, the fact that Taylor is caring for a child at all. Taylor spent most of high school trying not to get pregnant and stuck in Kentucky, and she addresses the irony that she's now saddled with a child, albeit one she comes to adore.