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1.
YCF
Acronym for "You crazy fool!" Can be used in oral or written communication.
-"Hey, where did you put that lottery ticket?"

"Man, I don't know, I might have thrown it away."

-"YCF!"
by Aussie goat February 22, 2006
 
2.
You Can't Fix Stupid
Ron White: But let me tell you something, folks: You can't fix stupid(YCFS). There's not a pill you can take; there's not a class you can go to. Stupid is forever.
by PrinceKelso May 12, 2011