A niche is essentially a place and conditions where one can thrive. This can be an elusive search, as we are all unique, with special abilities, experiences, and preferences. It would be nice if we simply could find our niche in society, but the reality is that some of us need to create it. This is not necessarily negative, as I believe it is people who create their own niche who propel us all forward through innovation.
If we all simply found our place, instead of making/creating it, then there would be no pushing the envelope, no challenging the status-quo, and society would enter a period of decay. Conservative-value politics and societies with nostalgia of a better past are similarly in a slow state of decay.
Plant a seed that is your dream- a seed that has never before existed, and you start the process of creation. It starts with an idea, record it on paper/computer to make it real, then start acting on it, little by little until it creates its own momentum, and becomes undeniable.