The quote describes the evolution of a concept within society's mindset over time. Initially deemed unimaginable, it transitions through various stages of acceptance, from absurdity to the recognition of its possibility and likelihood. This shift reflects a significant change in cultural perception and imagination regarding the idea.
By the time of the protagonist's birth, what once seemed impossible has become almost an unavoidable reality. This progression illustrates how societal beliefs can evolve, showcasing a shift from skepticism to an expectation of acceptance. It highlights the dynamic nature of ideas and the impact of generational change on perceptions of potential outcomes.