When I watched this video for the first time last year it was like a light bulb went off in my head. It is possible to be an Atheist without absolute, irrefutable proof there are, or ever have been, any deities.
The word Atheist does not mean complete knowledge that there are no gods; It means the BELIEF there are none.
It just so happens that as opposed to the belief there is a divine deity, based on minute scraps of historic writings and very large amounts of faith, the atheist’s belief there is no god is based on very large amounts of evidence and very little unknown.
An agnostic… someone who is unsure of what to believe either way… is not even the same animal.