The line comes from Forrest Gump, the 1994 film starring Tom Hanks as Forrest, who begins an impulsive run that eventually carries him back and forth across the United States. In the story he offers the simple explanation with complete sincerity, which helped the quote stick as a shorthand for doing something huge for almost no reason. Clips and captions quoting it spread through movie quote collections and later social video, where creators reuse the calm logic for marathons, road trips, chores and any commitment that escalates far beyond its starting point.