All this talk about event sourcing, and why it is the best. But who uses it? Why do they use it? And what are the challenges that others have run into? We had exactly these questions. In order to find the answers we have interviewed 25 engineers from all over the world. Some with many years of experience, others with just a few. In total they had 103 years of experience. We asked them all about event sourcing: why would you use it, why not, what did you like, what not, and so on. Topics such as schema evolution, optimization of replay, and the steep learning curve will be discussed. This talk presents a summary of 103 years of experience with event sourcing.