The meme "Because that's what heroes do" originates from the Marvel Cinematic Universe, specifically featuring Thor, played by Chris Hemsworth. This line is a sincere moment from Thor, a god-like superhero known for his valor and strength, as he justifies performing noble actions. The meme captures Thor's earnest expression, amplifying the humor when this grandiose superhero logic is applied to the trivial heroics of everyday life. The scene playfully flips the script, where Thor's epic reasoning is used to justify small, kind acts, making it a fan-favorite for its blend of sincerity and humor.