Back to the Future Day commemorates October 21, 2015, the specific date Marty McFly and Doc Brown traveled to in the 1989 sequel 'Back to the Future Part II.' The meme gained traction years before the actual date arrived, often appearing as a recurring internet hoax with photoshopped dates on the DeLorean's time circuit. Once the real date passed, the meme shifted focus to comparing the film's technological predictions—like hoverboards and self-lacing shoes—to our actual reality. It remains a staple of pop culture nostalgia, used to highlight how the future rarely looks the way we imagined it in the 80s.