"Confessions" by Augustine of Hippo wrote what many consider the first autobiography. The work is intensely personal and self-reflective and represents an encapsulation of the Western Christian tradition in its infancy. Most of the text is an autobiography of the author up to his conversion. He wrote this shortly after his elevation to bishop and so it should be properly seen not only as a personal autobiography but a defense of his theological positions which eventually would lay at the foundation of Western Christianity.

It is surprisingly emotional in many places. His path to God was not simple but agonized. It almost feels as if his entire being had to be brought forward piece by piece. I personally feel that the book is most effective in those moments of emotional and spiritual epiphany which led him along the path he went. It captures the reality of spiritual journey that no simple or sudden conversion story can capture. While I disliked last few chapters where he gets into more metaphysical speculations, it is an integral part of the wider narrative and give some of the ideas highlighted in the earlier chapters new depth.

Whether you are religious or not, I would recommend a reading of "Confessions" as an exemplar of autobiography and a text which shows many of the basic roots of Western thought.