If someone reports that he had been thinking that he would very much like to seduce his sister, an appropriate comment might be: “Shame on you for having such a nasty idea.” But if one reports that he dreamt he seduced his sister the situation appears quite different, for while we might be repulsed by the dream shaming seems, to say the least, far less appropriate.
We do not ordinarily, if ever, say things like, “It was bad (naughty, immoral, etc.) of you to dream that.” A child may be sent to bed without supper for saying that he hates his father, but not for reporting a dream which clearly expresses hate for his father.