By your reasoning, I would think, we can all be "masters of our own Destiny". And that would come about if we adhere to that old adage - "Know Thy Self" , yes ? Thus, one can ultimately master one's self and accordingly be in harmony with the Whole.
But surely no one can be Master of The Cosmos?
I recall in the 1960s or early 70s the fashionable premise that "Everything Is An Illusion". Well, subjectively speaking, maybe so.
But looking at things objectively, rather than subjectively, it's plain to see that we are all part of a greater Whole, whose Influence we can learn to allow to shape our awareness and our perceptions, and therefore our reason and our motivation and our actions - all for the Good, I trust.
Mysticism is a path which some do indeed tread, in their Search. But it is just one facet of Life and the Cosmos; one "window" - of which there are many, in my humble opinion.