I saw an episode of "Ally McBeal" and heard one character remark to the other about how they have had a lot of sexual harassment cases lately. And of course, since the entire premise of the show is to sexualize office politics in a titillating way, the reference becomes "meta." You want to say to the characters: it is the writers' fault!
The premise of "Murder she wrote" is that the main character will solve a murder that occurs in her vicinity, every week. This means that the murder rate in her small Maine town is going to be far worse than any big city. At one point, in an episode that doesn't take place in Cabot Cove, a character remarks about how many murders occur when she is around. Clearly, once you see Jessica Fletcher, you should get as far away from there as possible!
My third example is Snoopy's dog house. Why does he sleep on top of the doghouse, rather than inside of it? He gets rained on or snowed on, but doesn't enter the house itself. The reason is that we need to see him. Visually, the strip does not work if Snoopy is inside the dog house. So jokes about him getting snowed on and never escaping into his house, are also references to the conventional visual language of the strip itself.
I guess what I'm trying to get at here, is that a fictional universe will have its own rules, ones established by generic conventions rather than by the way things work in our, non-fictional universe. I think that's what gets Don Quixote in trouble as well.