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jormis29
Since: Mar, 2012
Freezer
Since: Jan, 2001

Need to know if this is an existing trope.
In the Simpsons, there was a throwaway joke where Iceland wants Homer's blood because he caused them to go bankrupt. Several seasons later, he goes to Iceland with no problem at all as if they forgot about it.
I don't think it's What Happened to the Mouse?.