Something initially Played For Laughs turns out to have a not so funny origin.
Say Bob has a problem. Alice,Carl, and...Matt make fun of him for it. Later in the story, it turns out Bob's problem is because of some horrible trauma as a kid or maybe a war and, of course, everyone is horrified and guilty.
Hello, Unknown Troper. You'll need to get known to lend a hand here.
Three days must pass before this YKTTW is Launchworthy or Discardable