Most of us in this thread now tend to agree that there are (at least) two kinds of atheism: Privative atheism ("undeclared atheism is misleading, as it suggests that the entity is possible of declaring, but hasn't) and what we have been calling "Considered and Rejected" atheism.
I have to wonder about the transition from one to another. Is there a time when you are both? Let's say that a baby is a Privative Atheist. As it matures it will eventually hear the concept of god(s), (although it may, like Claus, not remember it). But really, just hearing the concept does not actually mean that the child has considered it. Even with some ability to reason, a young child may struggle with a complex concept like theism. They may understand it partially or even incorrectly. During that time, does it make any sense to call them theists or atheists? Just because a child sings "Yes Jesus Loves Me" doesn't really mean that they are theist, but it would be hard to argue that they are atheists, since they have declared that they follow Jesus, even if solely because they were taught to say so.