We will make a journey into the origins of abstract interpretation 40 years later its publication in POPL 1977. Patrick Cousot will tell us the way this idea was conceived, what was the state of the art in static program analysis at that time, and how this paper changed the way we do program analysis and program verification nowadays. Anecdotes, problems, and successes of an extraordinary idea appeared 40 years ago in a paper which is the best ever cited of POPL.