Another thing I've wondered about infants being atheists is are they also atheists as pre-born fetuses, embryos, and zygotes? Are sperm and unfertilized ova then also atheists? Does the act of fertilization result in one becoming an atheist, or does it take being born to become an atheist? What about a premature baby - are they automatically atheists, or are they only considered atheists once they reach their original estimated date of delivery? It seems to be a complex issue, and I'm wondering exactly what criteria is used to define when a human being becomes an atheist by default.
For myself, I never remember sincerely or meaningfully believing in the existence of a god, yet I would say that I became what I would call an "atheist" over a period of time during my teens and early-twenties which involved seeking out, reflecting on, and exploring various areas of knowledge, which ultimately resulted in the rationalist conclusion that belief in the existence of gods was unwarranted based on my findings, along with corrollary conclusions, such as that it seems clear, logical, and rational that gods and religions are adequately explained by vagaries of human sociology and psychology.