Everyday Susan 

Referencing the popular TV show "Adventure Time." In the third episode of "The Islands" miniseries from the show in the eighth season, Finn the Human puts on insulating material to stay warm in a snow storm only for the weather to rapidly change. He has a large, almost Amazonian female companion named Susan who had appeared in many previous episodes. Finn makes allusions to her for humorous effect on occasion throughout the series. On this episode, once he gets warm, he says, "I'm sweatin' like an everyday Susan here." The phrase "everyday Susan" may at least subconsciously draw from the phrase "I'm sweatin' like a pig." Pigs are large and ungainly. In that way, Susan has some similarities. An everyday Susan may at the very least be somewhat of a bad connotation and/or a thing one would not necessarily want to be. A commoner, or a plebe, or an undesirable.

I'm sweatin' like an everyday Susan here!
Who does she think I am? An everyday Susan?
I don't know man. Not much there. Sort of an everyday Susan.

Everyday Susan by Stephen W. Hawking September 6, 2019