When we finally got our hands on the paper, we quickly realized that Einstein had put his finger on the essence of the problem and had delineated when it has a solution, before the invention of the modern quantum theory. Moreover, Einstein wrote with great lucidity about the subject, so that it seemed as if he were speaking directly to us, a century later. There was nothing dated or quaint about the analysis. For the first time in a long while, I found myself thinking, Wow, this man really was a genius.

Introduction: A Hundred Times More Than Relativity Theory - Einstein and the Quantum (2013)