Dreams may provide us insight to the subconscient springs of action that we suppress during our waking consciousness. Sri Aurobindo explains: “When we sleep and the surface physical part of us, which is in its first origin here an output from the Inconscient, relapses towards the originating inconscience, it enters into this subconscious element, antechamber or substratum, and there it finds the impressions of its past or persistent habits of mind and experiences,–for all have left their mark on our subconscious part and have there a power of recurrence. In its effect on our waking self this recurrence often takes the form of a reassertion of old habits, impulses dormant or suppressed, rejected elements of the nature, or it comes up as some other not so easily recognisable, some peculiar disguised or subtle result of these suppressed or rejected but not erased impulses or elements. In the dream-consciousness the phenomenon is an apparently fanciful construction, a composite of figures and movements built upon or around the buried impressions with a sense in them that escapes the waking intelligence because it has no clue to the subconscient’s system of significances.”
We see here then both a conservative power that continues to feed these old habits and impulses back into the awareness for quite some time after they have been consciously rejected, as well as an opportunity for our observation to understand the process of elimination and change of the outer nature that we undertake in the practice of yogic discipline. The observation of dreams and understanding the source and energy behind the symbolic or representational events we experience in the dream state can give us a clearer sense of how much work it takes to clear out this atavistic elements of our nature even when we make conscious attempts to overcome them, and gives us signposts of our progress along the way.
reference: Sri Aurobindo, The Life Divine, Book 2, Part I, Chapter 5, The Cosmic Illusion; Mind, Dream and Hallucination, pg. 423