The story
From the fictional place Lake Wobegon in Garrison Keillor's A Prairie Home Companion, where all the women are strong, all the men are good looking, and all the children are above average.
Etymology from Wiktionary, CC BY-SA 4.0.
Lake Wobegon effect
Today it means: Illusory superiority, that is, the belief that a majority of people are or can be above average. Full definition →