As this special issue shows, we know quite a lot about the workings of Photosystem II and the oxidation of water to molecular O₂. However, there are still many questions and details that remain to be answered. In this article, I very briefly outline some aspects of Photosystem II electron transport that are crucial for the efficient oxidation of water and require further studies. To fully understand Photosystem II reactions is not only a satisfying intellectual pursuit, but is also an important goal as we develop new solar technologies for the splitting of water into pure O₂ and H₂ for use as a potential fuel source. “As Students of the Past, We Send Greetings to the Students of the Future.”*