There is no rule of complete forgetfulness in the return of the soul to rebirth. There are, especially in childhood, many impressions of the past life which can be strong and vivid enough, but a materialising education and the overpowering influences of the environment must often, but not quite always, prevent their true nature from being recognised. There are even a number of people who have definite recollections of a past life. But these things are discouraged by education and the atmosphere and cannot remain or develop; in most cases they are stifled out of existence. At the same time it must be noted that what the psychic being mainly carries away with it and brings back is ordinarily the essence and effect of the experiences it had in former lives, and not the details, so that you cannot expect the same coherent memory as one has of past happenings in the present existence.
A soul can go straight to the psychic world but that depends on the state of consciousness at the time of departure. If the psychic is in front at the time, this immediate transition is possible. It does not depend on the acquisition of a mental and vital as well as a psychic immortality—those who have acquired that would rather have the power to move about in the different planes and even act on the physical world without being bound to it. On the whole it may be said that there is no one rigid rule for these things; manifold variations are possible depending upon the consciousness, its energies, tendencies and formations, although there is a general framework and design into which all fit and take their place.
Ref : Letters on Yoga Vol. I