Fantasy (n.) is a paradoxical subversion of the standard opposition of 'subjective' and 'objective'. It is neither objective (existing independently of the subject's perceptions) nor subjective (the product of subject's imagination). It belongs to the bizarre category of the objectively subjective the way things actually, objectively seem to you even if they don't seem that way to you.
Fantasy (n.) is fundamentally ambiguous. It is the screen which protects us from the encounter with the 'real' and so must must remain repressed in order to function.
Fantasy (n.) is structured upon the paradoxical 'objectively subjective.' it is, for example, consciously thinking one is well disposed to jews (subjective), but in fact is revealed to harbor serious prejudices against them (objective).
Fantasy (n.) literally teaches us how to desire. Every subject has to invent a fantasy of his or her own, a 'private' formula for the sexual relationship the relationship with a woman is possible only inasmuch as the partner fits this formula.
Fantasy (n.) tells me what I am for my others. It is always intersubjective. The child's fantasy of eating a cake is really a fantasy of being a good girl who is pleasing to her parents.