Another important intellectual shift concerned my expectation for certainty. If God exists, I'd thought, we should be able to be sure. I will have none of this “blind faith” nonsense. We should know it and be certain about it. And while I certainly did not come to accept faith as being blind, I did come to realize that this expectation of absolute certainty was entirely absurd. This standard is unreasonable, and it wasn’t hard to see: I realized there were many things I knew, and I was fully rational in my claim to know them while falling short of this utopian absolute certainty. I knew my name, my date of birth, and who my parents were. I even knew about things that happened before I was born: I knew that my older brother, Nicolas, was born through a C-section because the umbilical cord had been wrapped around his neck, and he came out “blue as a Smurf.” I knew that the Mont-Blanc is 4,807 meters high. I knew that the Bastille was stormed on a July 14—though I always forgot the year. And I knew there is a great wall in China—though I had never seen it. I knew all these things without proof and without absolute certainty. How? Because, in each case, someone who knows told me it was true. Yes, I came to see that personal testimonies are a perfectly valid source of knowledge—a source of knowing, not just believing.