It’s only right that cinema’s most flashbacked scene belongs to one of pop culture’s biggest icon. The champion of justice. The Caped Crusader, The Dark Knight, He is vengeance, he is the night. He is Batman! The most flashbacked scene is the night Thomas and Martha Wayne were gunned down in Crime Alley after seeing a Zorro movie (Or The Grey Ghost, if it’s the Animated Series, which counts because it had a theatrical release within the same continuity) by Joe Chill (Or The Joker if you’re Tim Burton). Usually it is done by having an Adult Bruce Wayne have a nightmare or explain his origin to an ally like when he recruits a new Robin. He goes through those like people go through underwear.
Usually it used to show that young Bruce Wayne also died and from the ashes rose the person who would eventually become the Batman.