This gets silly.

"Do you believe in woojits?" Well, no, I don't.

"Ah, well, if you disbelieve in woojits, then you must know what woojits are! So, what are woojits?" I have no idea.

"But how is that possible? If you don't have a definition for woojits, on what basis do you reject belief in them?" Having a well-defined notion of something is a prerequisite for belief in it; I don't have a well-defined notion of woojits; therefore I don't believe in woojits.

"No, no. You're confused. All woojit-disbelievers have to adopt a broad definition of woojits in order to disbelieve in them; otherwise they would merely disbelieve in a specific woojit." (shrug) OK, if you like, I have a broad definition of woojit... so broad, in fact, that it is effectively identical to my definition of all the other concepts I don't believe in and haven't thought about, which is the overwhelming majority of all possible concepts. For my part, I consider this equivalent to not having a definition of woojit at all.

As I say, this gets silly. It's just arguing about definitions of words.

Now, I would agree that atheists who grow up in theist cultures do have a definition of God, though I disagree with you that it's necessarily broad: I know at least one atheist who was raised Roman Catholic, for example, and the god he disbelieves in is the Roman Catholic god of his youth, and the idea that "God" might conceivably refer to anything else just doesn't have a lot of meaning to him.

I probably don't understand what you mean.

I think that it's easy to be an atheist -- i.e. one doesn't have to make any difficult definitions or arguments to arrive at atheism, and those easy definitions and arguments are correct. If you think it's harder than I do, that would be interesting and could explain why we have such different opinions here.