As above, so below. The human being finds himself, or herself, in the middle. There is as much space outside the human, proportionately, as inside. Stars, moons, and planets remind us of protons, neutrons, and electrons. I think it does.
Letters are symbols.
They are building blocks of words which form our languages. Languages help us communicate. Even with complicated languages used by intelligent people, misunderstanding is a common occurrence. Letters and words, calling out for understanding. Anger is usually present in arguments and fights.