Procrastination
Procrastination predates recorded history, with evidence suggesting its presence in early agricultural societies where planting decisions could be deferred until conditions seemed more favourable. The phenomenon has persisted through every epoch of human civilisation without diminishment.
Barring fundamental rewiring of human neurology, procrastination will endure as long as consciousness permits the contemplation of future actions. Its longevity is guaranteed by the architecture of the human brain itself, making it functionally eternal within human experience.
Superman
Superman has maintained continuous presence since Action Comics #1 in June 1938, representing one of the longest-running fictional characters in modern media. His persistence through the Depression, World War II, the Cold War, and the digital age demonstrates remarkable cultural staying power.
Nevertheless, Superman's longevity depends entirely on sustained commercial interest and intellectual property maintenance. Should DC Comics cease operations or cultural preferences shift dramatically, Superman could fade into historical curiosity within decades.