atheism is a couple of things for me..
-it's a reaction stemming from the feeling of deception upon one's discovery of some contradictions in a religion he may even not have chosen, and so disbelieves in theisms altogether, or god.
so instead of looking for different answers that may fit his troubling questions, he escapes by denying the question altogether.
-in the face of the harsh "realities" atheism forces it's adherents to accept, it drugs them with a large dose of ego to cope with them, and believe they are mentally more capable than the commoners and sheeple of the human race, enough to live "happily" with such realities.
an example would be the fact that all what we do according to atheism is, quite simply, for naught.
-in the spirit of the saying "when your only tool is a hammer, every problem seems like a nail"...
..."when your only tool is science, some nails seem like they do not exist"
science by definition deals only with what can be demonstrated and repeatedly[plus other criteria].
when one cannot think but by the scientific method, he is rejecting all aspects of reality which don't fit the scientific criteria, this of course is done only on hand picked subjects like god, but unless all atheists don't believe in history, they are accepting in their lives many things which fail the scientific test. then they proceed to worship the "how" they've studied so much instead of the "who", and assign to science the characteristics of god, from being behind the existence of the universe to being the most beautiful and amazing thing in our lives, as many admit publicly...a-theists indeed..
i believe agnosticism is the way to be, not only can you not prove god's non-existence, but the journey in search for god considering its importance is not one to end in an indifferent state(at best) such as atheism, agnosticism is the state between atheism and religion... which religion, that's yet to be determined.