The Interpretation of Dreams by Sigmund Freud Chapter 3 Page 8

which the analysis of dreams supplies. We learnt that the most intelligible and meaningful dreams are unrealized desires; the desires they pictured as realized are known to consciousness, have been held over from the daytime, and are of absorbing interest.

The analysis of obscure and intricate dreams discloses something very similar; the dream scene again pictures as realized some desire which regularly proceeds from the dream ideas, but the picture is unrecognizable, and is only cleared up in the analysis. The desire itself is either one repressed, foreign to consciousness, or it is closely bound up with repressed ideas. The formula for these dreams may be thus stated: They are concealed realizations of repressed desires. It is interesting to note that they are right who regard the dream as foretelling the future.