
Hello, Cory!
I am only familiar with dream symbols, and my experience is that they are very specific and personal, not only to the dreamer, but even to the dreamer's special circumstances. That is, you could dream of your oyster today and get a meaning according to your present situation. Then dream of an oyster 5 years from now and its meaning could have nothing to do with the first, unless... Oysters have a special meaning for you so that they come up in your dreams more often than usual -think oyster or any other personal symbol of yours-. That could mean you have integrated a certain element into your dream vocabulary and use it to represent certain situations, persons and/or, quite often, moods or feelings.
I believe phychic and cultural symbols are more permanent and widely shared. For example, we tend to associate an oyster and its pearl with something precious, delicate or hidden. Just a wild guess, though
