The Rayleigh‐Taylor instability has been the subject of detailed research for over 60 years, but what have we learned, and why has progress been slow? The answer lies in a combination of limited recognized applications, difficulties with performing experiments, and, perhaps the lack of walls! I plan to review progress over the last 60 years, and demonstrate how our understanding has been built, with asides that cover misconceptions, and the unique experiments that have been explored. Present day RT research will be discussed, modern applications (the continuing search for the presence of RT), and difficulties with experiments/simulation/theory. Remarkable progress with RT research, and application, has been made over the past 25 years, but there are still significant opportunities for RT research that will be discussed.