Diwali is the most awaited festival of India.
Brihadaranyak Upanishad says "Tamaso ma jyotir gamaya.." lead me from darkness to light.
In my understanding this means lead me from absence to presence.
Darkness does not have an existence of its own, its rather the absence of light. But this negative presence severely impairs our judgment. The absence is a "negative presence". The absence can be perceived as disturbance, as lack of something vital. We can’t discriminate, we cant perceive and the sight sense gets hampered if light is taken away.
The absence of awareness is mind, the presence of awareness is bliss(self/aatman).
This constant burden called mind impairs our judgment about reality.
Our own presence is the light. By adding ourselves(light) to our thoughts (darkness), darkness disappears.
This is the subtle essence of Ramayana, the vanvaas might be too, long too dark, too tough, the demonic thoughts might be too depressing (anxiety/worry/fear/greed/impatience) they cant last if u are present This presence comes by persistence.
This is the homecoming of Rama the journey of Self back to itself.
Incidentally Dipawali falls on the amavasya of Ashwin Maas(month). Just the when the darkness gets complete(amavasaya) ,when the thoughts push the depression to pinnacle, the new moon rises and the awakening happens.
Incidentally this is the day when Vardhamana became Mahavira. He conquered no kingdom but became the conqueror of self.