Somehow, I made it to over 30 before I met another atheist (who I knew was atheist) in person. I'm not sure how long I made it before discovering another person who was openly atheist at all, but I do know it was a very long time. I later learned that one my closest friends since junior high was an atheist but hadn't said anything to me about until 18 years later, but that's a story for another day.
Even by the time I learned about the lawsuits Michael Newdow was filing I didn't know about many atheists. I had been an atheist my entire life, and the word atheist was still quite foreign to me. I was barely even really that aware of the existence of other atheists.
I had long since stopped saying the Pledge, for two different reasons. I didn't know the term "nationalism" then, but I apparently could recognize it when I saw it, and, to me, t felt creepy
My other problem with the Pledge was the same problem most atheists have with it. The phrase "under God". Having learned about the Freedom of Religion, I knew religion and government were supposed to stay out of each other's business. It bothered me, but I never did anything about it.
Michael Newdow did. He sued to try force his daughter's school to do the right thing.
He gave rational reasons for why he thought this fight was worth fighting and why he was on the right side of it. But, like everyone else on the right side of this fight, he was vilified for it.
He hasn't won the overall fight, but he hasn't stopped fighting it. Among his other activities, he is currently on the Advisory Board for the Secular Coalition for America. The Secular Coalition for America is fighting a fight that shouldn't even need to be fought, considering the answer is in the Constitution our opposition pretends to revere. But I'm sure glad they're fighting it.