Why do people dream? Does this affect dream interpretation?
Freud conceived of dreams as the manifestation of how we attempt to digest information in our subconscious. From this perspective, deciphering the content of a dream means being able to get in touch with information that is important, but difficult for our conscious mind to access.
As neuroscience started exploring dreams from an experimental perspective, some findings suggested that dreams may actually be random (i.e. not be related to meaningful information processing). Then, other studies suggested that they may actually be! So there is currently no consensus as to whether or not dreams are a language that accurately reflects the issues in our minds, as opposed to random images.
Does this mean that we cannot benefit from paying attention to our dreams? Not at all.
You're familiar with the Rorschach test: you look at inkblots, and describe what you see, whereby reflecting what's on your mind. Your dream functions as such a point of departure. It certainly feels more poignant than an inkblot because it contains imagery that is pertinent to you: You have singled it out from many other dreams to actually remember it (we all forget the vast majority of our dreams, so what we remember is special).
In other words: The fact that you remember the dream is a sign that there may be something of importance to you in it. Uncovering its meaning is more akin to exploring what Rorschach inkblots mean to you than to translating a text from a different language (say, the way you would translate Spanish into English, or hieroglyphs into English). Instead of looking for standardized dream meanings, it is far more powerful to explore what dreams mean in the context of your own life.
This creative process is outlined in the page about Creative dream interpretation: How to understanding the meaning of dreams. You can also listen, below, to a radio interview in which I describe this process.
See: What is the meaning of your dreams? Features continuation of the above interview (creative dream analysis, live on air), and another creative dream analysis video.