The mark of the psychoanalyst
Of desires there are a great variety but desire to know what the unconscious could tell us about jouissance as castrated, absolutely not!
Lacan asserts in Encore that there is no such thing as a desire to know, this knowledge proper to the unconscious, and he adds, in his “Italian note”, that all of us, the entire humanity, we are horrified of this knowledge.
Where psychotherapeutic practices only reinforce this horror of knowledge, the analytic offer promotes a desire for unconscious knowledge about sexual reality and castration. This knowledge, already there but encoded, is to be deciphered by the interpretation.
Beyond the deciphering, the analysis also invites a desire for knowledge proper to the psychoanalyst, one that has to be invented since unlike unconscious knowledge “it is not cut and dried”. 
This is what sets the psychoanalyst apart from the rest of humanity, this would be his mark, he to whom the desire for this knowledge that is proper to him would have come.