It's my opinion that every adult can lay claim to being the "first" or "best" in the world (or at least the country) at something. In much the same way that probably 95% of everyone asked would consider themselves to be an above-average driver, making this claim can sometimes require a little bit of self-deception, but no real harm is done.
For me, my claims to fame are that I run the world's most popular submarine blog, I was the fastest ever submarine Engineer on Alpha Trials (at least in the U.S. -- it depends on if the Soviets let their Alfas get up to flank on their initial sea trials, which I kind of doubt), and I lay claim to having written more Admiral's letters enclosures than any Eng in the history of the Submarine Force. (I wrote about 60, having been initial manning Eng twice; letters were due every 4 weeks in the shipyard.)
What's your claim to being the best?