The details differ, but the story arc of how Mark Jaquith became an atheist mirrors my own. Raised in a traditional Roman Catholic household, on the best days my religion bored me, on the worst, it made me feel like a terrible sinner. Every day, its contradictions and lack of fact-based logic troubled me. I felt no connection to or appreciation for the culture or community of the Church, especially its patriarchy, homophobia, and focus on sin and repentance. My parents were very religious, so I endured 12 years of Catholic school wearing a pleated plaid skirt and fearing the nuns who were my teachers. Dad was an usher, Mom a Communion minister, my brothers altar boys. In addition to Sundays, I daydreamed through morning Mass every weekday before school with Mom. I studied Latin (the only part I don't regret).
As an adult, after years of alternating between questioning and not caring, Richard Dawkins' The God Delusion changed everything. Like Mark, becoming an atheist was an intensely clarifying transition for me. It was as if I put on glasses and saw the world clearly for the first time, after suffering from a severe case of myopia my entire life.
Mark's post is lengthy and not fit for the easily offended, but fully worth the read in a quiet place with an open mind.