How do symbols form?

I understand what Frye has to say in his "Theory of Symbols" from a few examples I've read so far. He mentions that a dictionary would be useless if we did not already have some knowledge of others words. I understand this notion to be explained further in thinking about how we can't totally comprehend the meaning of a word until we picture it. We do not have a complete understanding until the picture or "symbol" gives us an image to base a definition or description of off. Even then it's still a continuing form and shape that floats aimlessly until we attach it the best definition of it we view as the most qualified. Frye uses a cat as a symbol that is broad enough to float through different meanings and different personal attachments to the symbolic meaning. At times a symbol gets confusing in how the text means to show it or how the author of the text meant to use the symbol in relations in textual imagery. "The reality-principle is subordinate to the pleasure-principle" can sum up all that is learned when constructing a symbol in reading literature. It seems that a common reaction to that phrase would be "of course!" It may not be though. If literature at it's most basic operation in the universe "instructs and entertains" then why do we need answers to know which comes first? The pleasure in being entertained surely dominates the recognition of feeling more knowledgeable while reading. In a way it also disguises infusing knowledge while being entertained. In thinking about how we forms symbols or how the symbols form the meaning of what we read I would recommend consulting your consciousness differently. Don't think about how the symbol comes to makes sense after reading, think about how the symbol makes more sense as the reading continues. It makes more sense because a symbol has multiple meanings and it would be impossible to dissect which ones induce the pleasure-principle and which ones induce the reality-principle or the learning principle.