Depends on Food, Health and Psychology.
Food: Did you ever notice that when you take a nap after you've eaten lunch that you can have some crazy images go through your mind. The same thing happens at night too, because food can trigger some wild and wacky dreams. If you enjoy these psychedelic excursions, then take note of what you had to eat before hand and repeat the process. On the other hand, if you're not interested, then take note of what you ate and make certain to avoid eating whatever it was. Food is one of the generators of dreams, which are not worth interpreting.
Health: Your subconscious knows a lot about you that you don't, or maybe don't care to know. Often times it will tell you something about your practices or lifestyle to tip you off about what its needs are. In dreams it tries to get the point across to you, sometimes politely, at other times not so.
Psychology: Stressful relationships and social situations can cause our mind to get out of kilter but our subconscious intervenes to straighten things out
Also Read: Dreams from the spiritual realm
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