It would seem that the analyst by repeatedly asking “why?” becomes associated, in certain cases, with a desire to know why. Lacan1suggested that our general attitude in life is a will not to know: not to know what ails us, not to know why we do what we do, not to know what we secretly seem to enjoy, not to know why we enjoy what we enjoy, and so on. A strong motive, a considerable investment, is required for us to overcome that will not to know, and one of the trickiest tasks for the analyst is to find a way to inspire in his analysands such an investment. Perhaps it is at least in part the analyst’s will to know, as demonstrated in his continual questions, that inspires a desire to know in his analysands; it is his persistent asking of questions that allows him to become the cause of the analysand’s wondering, the cause of the analysand’s desire to know why.2(35)
 Lacan, Jacques. The Seminar of Jacques Lacan Book XX: On Feminine Sexuality: The Limits of Love and Knowledge (Encore 1972-1973). Trans. Bruce Fink. Ed. Jacques-Alain Miller. W.W. Norton & Company, Inc. 1998. Pp. 1.
As I have indicated elsewhere, it is the point at which the analysand formulates broad questions of her own about the why and wherefore of her direction in life that marks the end of the preliminary face-to-face meetings; in other words, this is the point at which the analyst should consider moving the analysand to the couch.
The analyst must, of course, be careful not to ask so many questions as to begin to direct what can and cannot be talked about in sessions. The general topics addressed and direction of sessions should be left up to the analysand, except when she is obviously avoiding important work.
Fink, Bruce. Fundamentals of Psychoanalytic Technique: A Lacanian Approach for Practitioners. W.W. Norton & Company 2007.