The Interpretation of Dreams by Sigmund Freud Chapter 6 Page 21

Thus, the force of expression of the wish-fulfillment is diffused over a certain sphere of association, within which it raises to expression all elements, including those that are in themselves impotent. In dreams having several strong wishes we can readily separate from one another the spheres of the individual wish-fulfillments; the gaps in the dream likewise can often be explained as boundary zones.

Although the foregoing remarks have considerably limited the significance of the day remnants for the dream, it will nevertheless be worth our while to give them some attention. For they must be a necessary ingredient in the formation of the dream, inasmuch as experience reveals the surprising fact that every dream shows in its content a connection with some impression of a recent day, often of the most indifferent kind.