A single breeding pair, a calendar year, and a question that has echoed through mathematics classrooms for centuries — BBC Wildlife Magazine has returned to the rabbit thought experiment to remind us that exponential growth is not merely an abstraction but a force that reshapes ecosystems and challenges human understanding. Rooted in the medieval work of Fibonacci and carried forward into modern ecological science, this puzzle endures because it makes the invisible mechanics of population dynamics suddenly, viscerally visible. The math is simple to state and humbling to follow.