An article in the March 22, 2023 issue of The Wall Street Journal ("Choose What to Dream Tonight") suggests that a person can guide their dreams but I'm not so sure. The unconscious is powerful and, despite all the electronic gadgets used in brain research, one must respect its power. Elements in dreams arise from recent events like a movie viewed or long ago memories. If, before falling asleep, you tell yourself you will have a dream and remember it (as I advise patients to do) you'll be more likely to but this isn't certain since mental operations are complex. If you don't write the dream down upon awakening you likely won't remember it later since the conscious logical part of the mind largely takes over mental functioning then from the unconscious illogical part that creates dreams. Nightmares, which are very emotionally charged dreams, are remembered longer and common. Those unreceptive to dealing with their unconscious conflicts will tend not to remember their dreams, and dream remembrance seems also affected by some medications.