@SarahGen-- I definitely see your point. One issue that occurs when trying to analyze a piece of work that was written in another time frame and another culture is that we are just not familiar with it. There are certain symbols and trends in every decade and culture which also finds its way in literary works. Not knowing what does are makes it difficult to make an accurate interpretation.
For example, Hamlet is actually a religious allegory about the Protestant Reformation. But it's difficult to see this without knowing that the Reformation was the hot topic of debate at the time.
There are also symbolic words and phrases in Hamlet, or words with double meanings, that one cannot know without being familiar with how people spoke at the time.