Quick note to the posters so far, there isn't a difference between "agnostic atheist" and "atheist". They're both atheists in the same degree (the only degree possible), it's just that adding the term "agnostic" is more descriptive of the position held than simply stating the uber-general "atheist".
I was raised Presbyterian, though it certainly wasn't a die hard religious home. My father didn't attend church (although I had no idea why when I was attending church myself) because of the poor experiences he had going to catholic school and coming from an extremely catholic family. I never really consciously thought about the fact that he didn't attend church with the rest of us, it's just kind of the way it was, but this was important because I knew at least at some level that some people didn't go. I did believe that God created everything and that Adam and Eve really existed because that's what I was told, and I was young enough that school hadn't yet taught me anything that would contradict such nonsense. Believing what adults told me was pretty much my only means of learning, and I saw little difference between the adults at Sunday school and the adults at elementary school.
I was never very focused on religion, believing that God was a real thing was just part of my life, not really any different from believing that plants grew, the sun rose through the forest on the east side of my house, or that my dad drove a Subaru. God wasn't an optional belief or something to question, but neither was it something in need of questioning or defense. It just was real. I even remember thinking that I felt his presence, especially in church.
I remember quite well the day that I made my mother confirm my suspicions, and tell me the truth about Santa, the Easter Bunny and "all the rest of them" (as I'm pretty sure I put it). I had begun to understand that not all of the stories we're told about the way the world is are fact. Most are just as fictional as the fairy tales I had known were just stories. I would remember feeling the same way about biblical stories a number of years later.
My school studies progressed, somewhere along the way I was confirmed to my church, and somewhere along the way I stopped going to church. It wasn't odd, it was just what my dad had done my whole life. I was going to school an hour away from home, and I was doing extracurricular music studies in addition to school and sports. There wasn't time for much else. It's tough to remember what you didn't think about, but I'm pretty sure there was a period of time where I just didn't think about God at all. School had advanced enough that I was beginning to encounter real explanations for things. These weren't stories. I was only presented demonstrable facts, and reasonable interpretations of them. I began to develop a love for history and strategy and critical analysis. As a result, I gained a pretty decent (for a middle schooler) understanding of how we know things, the consequences of means of discovery and application of knowledge, and I knew how to present this information. Who knew that chess and Magic the Gathering would translate into debates about extraterrestrial life? It was in that very debate (which was not prepared, and rather spontaneous in an literature class of all things) that one student presented the Drake equation to assess the probability of there being life beyond our planet, and his opponent presented the brilliant arguments, "all life must have oxygen to breathe, and there isn't oxygen is space" and, "God made this universe for us, and not anyone else". I remember two things: feeling astonishment that my math class was relevant in my life, and that the two arguments the latter student presented were equally unfounded and stupid.
I was an atheist before I had even heard the term.
I didn't know that I should identify as an atheist until much later. I'm not sure entirely when, but it was near the end of high school or the beginning of college. I had heard vague stories about people battling the teaching of evolution, but I payed them little heed. It wasn't until one of those "deep" conversations new college buddies have in the middle of the night that I thought I should apply some critical thought and research into what all the hubbub around this issue was. Funnily enough, it was around that time that I began posting on TW, and soon after that, I was posting in the old Evolution vs Creation thread. With my passion for debate driving my research, and the internet at my fingertips, I gained a full understanding of what atheism actually is, and better fleshed out my own position on these questions. Thanks to Arch I began to follow Hitchens and Dawkins, and thanks to Uther I spent hours on youtube listening to TBS, dasamericanatheist, and everyone their channels led me to.
And now we're here. And I'm writing the scripts for four videos, which may not go up for months.
My dad, who I didn't really talk about religion with until recently, has fallen in love with Sam Harris and (just the other day) Hitchens. My mother has always been more "spiritual", and claims that she only took me and my sister to church because she felt that it was important to know about "that stuff". I don't really believe that, but she is grudgingly reading The End of Faith, and grudgingly agreeing with most of what she's read so far. We'll see what she says when she finishes.
Holy **** that was long.