This should already be clear to you:
-The shadows of ideas projected on the wall = opinions, illusions.
-The wall = the material world seen by us.
-Ideas are the basis of reality and not the material world.
The most important thing you can do is: ' Know thyself', practice self-reflection, learn more about yourself than what you believe you are.
Here I will go further:
The material world is largely an illusion, it is always changing. By just looking at it, one cannot learn anything.
There is also another world: an eternal world of ideas. It is made up out of eternal unchanging forms of things. This world can be known through reason alone. The material world (world of things) is a manifestation of this eternal world of ideas.
Using the allegory, Plato pictures the everyday situation of man. He can speak, hear, and encounter the world without actually being aware of the world of Ideas.
True knowledge can only be gained from the world of ideas. The world of things merely generates opinions or illusions. lato depicts these worlds as existing on a line that can be divided in the middle: the upper part of the line is the world of ideas and the lower part is the world of things. Each region can further be divided in two. In the world of things, there are “illusions”, which composes the lower region, and “beliefs”, which composes the higher region. The illusions are the shadows represented by the artistic works of the craftsmen and poets. The beliefs are man’s knowledge of individual things, which may sometimes be true but is often times false because individual things are constantly changing. The world of ideas, on the other, can be divided into “reason” (the lower part of the region) and “intelligence” (the higher part of the region). Under reason is the knowledge of things like mathematics. And under intelligence is the knowledge of the highest and most abstract categories of things, for example, understanding the