Victory over the dragon

One of the oldest legends is the victory over the dragon.
Heroes like Prometheus; they all joined in the battle with the dragon, symbolizing evil.
This myth we encounter in different cultures, the most sacred legends.
Let's consider the version of the myth of the Vedas. 

In the Vedic belief, Vritra appears as a dragon that holds the heavenly waters.
These Water – way by which the people raised in the world of the gods, and the gods descended to the human world.
Vritra (meaning barrier) - are an enemy of Indra.
Indra, the Vedic God (radiant), defeat dragon, freeing the PATH, an opportunity for people to climb into the upper world.
What must mean this victory over the dragon? Why is this image so important?
In my opinion, a place where there is a war - is the depth of the human soul. The dragon is "lizard brain", base instincts.
That is why in some myths the heroes manage to barely win, almost turning into a dragon himself.
When looking from this angle, the whole history of humanity will appear in these symbols, with an UNPREDICTABLE end, because the fight continues, and nothing indicates that dragon in each of us will be defeated.
Defeat the evil within ourselves. Release the chained giant within us, this is the essence of such myths.
I was given a book, in my childhood, with such a myth. Watch my video about