I enjoyed the youtube clip posted by botchtowersociety.
Also the comments by thinking_1 Both on page 2.
Also enjoyed the link posted by leavingwt and many other contributions from others.
As for the opening question: How Did You Become An Atheist? I too prefer not to wear a label and be suddenly viewed as belonging to an organisation. I realised that God, as promoted by major religions, does not exist, 9 years before I left Jehovah's Witnesses at the age of 30.
I examine Christianity but realized that without belief in God I would make a poor candidate. An examination of Eastern religion and philosophy was more promising. I have some respect for Zen Buddhism and Tao. In the end though, I do not see a shred of evidence that an Abrahamic God exists or any other personal God. God is AWOL. It’s the no-show factor that convinced me.