The Indian festival of Diwali is celebrated for a number of reasons. Legend has it that Lord Krishna slew the demon Narakasura on this day, and thus, Diwali has been celebrated every year to commemorate the event. The story comes wrapped in multiple metaphors. For one, the demon is symbolic of all the negativity that we carry within us - anger, fear, hatred and other debilitating emotions. Krishna represents the awareness and possibility that we hold within ourselves to destroy these troubling aspects of ourselves.
Thus, the Bhagavad Gita quotes Krishna as saying: "Those who overcome the impulses of lust and anger which arise in the body are made whole and live in joy. They find their joy, their rest, and their light completely within themselves." Once these "dark" aspects are destroyed, joy, happiness and light are a natural outpouring from within us.
The Gita is quite explicit in stating that joy arises completely from within. Happiness is not something that is given to us from the outside by someone or something else. In our current situation, we may experience happiness only in certain situations and thus equate happiness to the presence of someone or something. But essentially, joy is born from within us. It is an experience that we create for ourselves. This creative power becomes stronger and more enduring once we remove negativity from within.
Swami Vivekananda, who introduced the Western world to Eastern spirituality and philosophy during an epoch-making speech in 1893 at the World Parliament of Religions, Chicago, has also remarked on this. One of the most famous quotes of Swami Vivekananda states: "All the powers in the universe are already ours. It is we who have put our hands before our eyes and cry that it is dark." So, it is really up to us to take our hands off our eyes and experience the light. This is symbolically represented by the tradition of lighting lamps during the festival. By lighting these lamps, we dispel the darkness, just as we can light the lamp of clarity within to dispel the darkness of ignorance.
Another aspect of Diwali is the celebration itself. The whole idea of festivals is to make celebration a way of life, rather than a once-in-a-way affair. I suppose it isn't really feasible to declare every day a holiday, so certain days of the year were earmarked, but that doesn't mean we celebrate on just these days alone. Making our whole life into a celebration is an important aspect of Indian festivals, and Diwali epitomizes this in many ways.
This ultimately ties back with my earlier point about finding joy and happiness within us. When we celebrate, we are naturally joyfully. So, making our life into a celebration is an easy way to make joy our constant companion.
I guess that's what all the crackers are for - to make the life within us an explosive concoction! The sooner we get these fireworks going inside, the sooner we can cut down on the fireworks outside and reduce both the noise and pollution!