In science, one needs to have a eureka moment from time to time, in order to avoid falling into depression—it is not easy every day to be a researcher. Sometimes, these eurekas are the result of SERENDIPITY. However, in most of the cases, these eurekas are the result… of (experimental) RESULTS, that is, of WORK. But there is another category, the GREAT EUREKAS, that do not hit your mind many times in your life. I believe that I had only one GREAT EUREKA that, however, dictated my projects, experiments and successes for several decades.
Lluis M. Mir (Fri,) studied this question.