Perception of predeterminism
Feelings of predeterminism can be defined as the sudden perspective or feeling that all events, including human actions, are established or decided in advance by prior causes.
This is a perspective that can become spontaneously triggered and felt through a distinct change in thought processes. In terms of how it feels, the perspective can be described as the assumption that ones internal narrative possesses "free will" and is therefore an independent decision-making agent becoming revealed as entirely illusory.
This revelation is not a result of cognitive insight leading one onto a realization but occurs through a forced change in perspective. It creates the undeniable sensation that ones personal choices, physical actions, current situational perspective, and the very subject matter of their thought stream has always been completely predetermined by prior causes and are therefore outside of conscious control. Instead, ones thoughts and decision making processes are felt to act as a vast and complex set of internally stored, instantly decided, pre-programmed, and completely autonomous mechanistic responses to perceived sensory input and not a product of free will.