It depends on the connection between the two states of consciousness at the time of waking. Usually there is a turn over of the consciousness in which the dream-state disappears more or less abruptly, effacing the fugitive impression made by the dream events (or rather their transcription) on the physical sheath. If the waking is more composed (less abrupt) or, if the impression is very strong, then the memory remains at least of the last dream. In the last case one may remember the dream for a long time, but usually after getting up the dream memories fade away. Those who want to remember their dreams sometimes make a practice of lying quiet and tracing backwards, recovering the dreams one by one. When the dream-state is very light, one can remember more dreams than when it is heavy.
It is good that you go back from this struggle towards the quiet foundation that helps the opening. All this struggling and confusion and harassing self-depreciation is the old wrong way of proceeding; it is mental and vital and cannot succeed; it is in the quiet mind that the opening must come. Then the psychic being, the soul in you begins to come forward. The soul knows and sees the Truth; the mind and vital do not -- until they are enlightened by the soul's knowledge.
Immortal to the rapturous heart and eyes,
In serene arches of translucent calm
From Wonder's dream-vasts cloudless skies slid down
An abyss of sapphire; sunlight visited eyes
Which suffered without pain the absolute ray
And saw immortal clarities of form.
Twilight and mist were exiles from that air,
Night was impossible to such radiant heavens.