Have you noticed what I have?

	Mathematicians can't do arithmetic.
	Physicists are uncoordinated.
	Computer scientists don't use Windows.
	Theoretical computer scientists cannot write benchmarking code.
	Doctors lead unhealthy lives; they don't sleep enough; they smoke.
	Psychiatrists are crazy.
	Social workers' families are dysfunctional.
	Spiritualists are trying to take your money.
	Humor researchers are not funny; they have bad timing.
	Philosophers couldn't care less about wisdom.
	Among linguists:
		Syntacticians speak in incomplete sentences.
		Semanticists can't hold a coherent conversation.
		Phoneticians are deaf (includes me and my phonetics professor).
	Both geneticists I know have adopted children.
	My friend the underwater photographer is fat: he floats.

Or What Darius noticed?:
	Data scientists are biased. 
	Fisher invented modern statistics; rejected its results; died of lung cancer, a smoker.
	Software engineers are illogical.
	Shoemakers wear worn-out shoes.

Is this evidence for a general theory of professional incompetence?  Hmm...