If everything we experience is a construct of the mind, then fate and destiny are made up concept by human to understand various aspects of his / her existence. Both probably have deep religious origins and could have gained prominence as means of exerting control over populace. A great way to feel comfortable knowing god willed it so it must be out of my control.

The more likely reality is that we move through space like animated objects looking for meaning where no meaning exists. We’ll do anything that brings us comfort, including making up concepts that allow us to not take responsibility for our actions and create excuses for various forms of abuse.