" If the ego succeeds in protecting itself from a dangerous instinctual impulse, through, for instance, the process of repression, it has certainly inhibited and damaged the particular part of the id concerned; but it has at the same time given it some independence and has renounced some of its own sovereignty. This is inevitable from the nature of repression, which is, fundamentally, an attempt at flight. The repressed is now, as it were, an outlaw; it is excluded from the great organization of the ego and is subject only to the laws which govern the realm of the unconscious. If, now, the danger-situation changes so that the ego has no reason for fending off a new instinctual impulse analogous to the repressed one, the consequence of the restriction of the ego which has taken place will become manifest. The new impulse will run its course under an automatic influence—or, as I should prefer to say, under the influence of the compulsion to repeat. It will follow the same path as the earlier, repressed impulse, as though the danger-situation that had been overcome still existed. The fixating factor in repression, then, is the unconscious id's compulsion to repeat—a compulsion which in normal circumstances is only done away with by the freely mobile function of the ego. "
― Sigmund Freud , Inhibitions, Symptoms and Anxiety