•Why it earns a slot
Widely considered the first true autobiography in Western literature, and the source of an enduring question, why would anyone sin with no benefit at all, that still gets cited in discussions of motiveless wrongdoing.
Augustine wrote the Confessions as a direct address to God, recounting his own moral drift through youth, a mistress and illegitimate son, years devoted to a rival religious sect, and a long resistance to Christianity before his eventual conversion. Its innovation is treating an ordinary person's inner life, doubt, temptation, and self-deception, as worth this much sustained, searching attention.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.