see that guy trying to put that square peg into that round hole?  i think he's gone coo coo for cocoa puffs
a strictly medical term, used to describe a patient or person that has delved into a realm of irrational, illogical and/or crazy thought processes
"see that guy trying to put that square peg into that round hole?  i think he's gone coo coo for cocoa puffs" What is the definition of "coo coo for cocoa puffs"?