When we say ‘crazy’ we really mean something totally different from the meaning of the word.
Middle English to ‘craze’ is to break or to crush. English literature is full of crazy ships sinking and crazy pitcher unable to hold water… Towards the 1570s, crazy came to represent sickened people and when did the ‘cool’ jazzy slang we now use came about? Only in 1927!
And crazy in terms of nuts? Doesn’t even seem to have this definition!