Understand that Kwanzaa is an African gift to the world. it is a direct effort to uphold African responsibility of self determination and value proposition within the universal ecosystem.
and if someone ask why we celebrate.
You may proceed with confidence and say because of Kujichagulia (Self-Determination): To define ourselves, name ourselves, create for ourselves, and speak for ourselves.
and when they say it is fake...
You may remain in composure and say indeed, it is a proud invention of Maulana Karenga who had the foresight to see; like many other such 'inventions of tradition', the creation of an American Christmas was a response to social and personal needs that arose at a particular point in history, in this case a time of sectional conflict and civil war, as well as the unsettling processes of urbanization and industrialization.
Kwanzaa is a new holiday with new customs and new meanings designed to help the nation heal the wounds of its society from its atrocious past, if only for a short while each year, a soothing feeling of empathy, remorse, acknowledgement of truth, forgiveness, peace and unity.
If you still think it is fake, see the consciousness of this young girl's essay. Some may see despair while others see determination. Either way, the objective is healing and nurturing. This is what Kwanzaa is about. We wish you Happy Kwanzaa. — with Africans InPower.