When a character (primarily in dramas) is asked to go beyond their job and help with "a cause", the character sometimes refuses, and afterwards the other person asks, "What's happened to you?" or "Since when did you stop caring?" the answer sometimes comes down to the character saying, "I grew up," implying that the character "grew" from a Wide-Eyed Idealist to an embittered pessimist. It's also often used by the Anti-Hero or Nietzsche Wannabe to sneer at the idealistic methods and beliefs of the Ideal Hero and his ilk; such naive and childish wishful thinking has no place in the grown-up, random, cynical world that the Anti Hero lives in. Alternatively, a Retired Badass might have genuinely gotten too old or set in retirement to do what's being asked of them.