In analysis, the exploration of our destiny is more gradual, more self-reflexive. [...] the point is not to obliterate our foundational destiny (or fundamental fantasies) but merely to elaborate it in more satisfying directions, away from the incapacitating effects of the repetition compulsion [away from the death drive] and toward the rewards of subjective autonomy.
Lacan holds that beyond all the myriad images which appear in dreams and elsewhere there is always one "fundamental fantasy" which is unconscious. In the course of psychoanalytic treatment, the analyst reconstructs the analysand's fantasy in all its details. However, the treatment does not stop there; the analysand must go on to "traverse the fundamental fantasy." In other words, the treatment must produce some modification of the subject's fundamental mode of defence, some alteration in his mode of jouissance.
An alteration to the fundamental fantasy is something that takes time, you can't microwave it.
I've compared it to changing the way a person orbits the blackhole of their eventual and unavoidable death.
It's a big deal.