Hyperbole (an extreme exaggeration used to make a point)
-this bag weighs a ton!
-I’m so hungry I could eat a horse!
Adynata (an extreme of hyperbole into impossibilia)
-I will do that when hell freezes over
-yes, he will come and pigs will fly
Interestingly, the term bootstrapping is derived from an adynaton: you can pull me over the fence by my bootstraps.
It seems fitting that a term used to describe a startup practice should be derived from hyperbole into impossibilia.