Jesus notes that before the Great Flood, people went about their normal daily routines—eating, drinking, marrying, and planning for the future—completely unaware of the impending shift until Noah entered the ark and the deluge arrived. The central theme of the comparison is not merely moral decay, but the complacency and suddenness with which judgment or revelation occurs. People were preoccupied with the mundane rhythms of life, blind to the spiritual reality around them.