Dreams and memories are not absolutely true. What are dreams? We try to understand dreams by interpreting them and dream interpretation is done by analysing dreams according to personal knowledge, experiences (which are memories), our culture, imagination and intuition.
How can a memory be responsible for a dream? A memory is dynamic. It is a small bit of our past, which is also influenced by additional factors which impact on our present. We are elaborating on this.
A memory is not a straightforward piece of our past experience. Recalling a memory is a combination of a fuzzy recollection of our past, coupled with our present version of what we think happened. The power of suggestion is strong. Suggestion introduces doubt. We begin to wonder if we indeed experience such a memory. Suggestion creeps in to influence us into thinking it seems like we did experience such an event when actually we did not.
Time is a cheat. Time creates false memory. Time masks the true impact of a past event, to render it less stimulating, less stressful and loosens its impact on us. In other words, the passage of time makes us forget and thus heals wounds.
Some dreams are suggestive. They make us doubt if the dream retells a true episode in our life. If this dream replays often, it becomes a recurrent dream that does not let go of the theme as long as it remains a concern in our mental and emotional realms. We may come to question if the theme is a truth because of its tenacity to repeat its appearance in our dreams.
Reference
Ranganath, C. Why We Remember The Science of Memory and How It Shapes Us.