Why do we have festivals ?

So why were festivals introduced ?

Is it merely just the celebration of good over evil ? Or does it have another tacit reason - was it introduced by some set of 'intellectuals' so that people will get a break from their regular schedules, altercations forgotten, moods refreshed and fueled up for another few weeks or few months ?

Just a thought!

Happy Bhogi! Happy Pongal! Happy Holiday!