The concept of "reality", of a physical universe, of a "you", of order and pattern, of an persistent objective reality outside of you, do not exist per se, but as simulation and models in your mind that you accrued throughout your life.
To be more specific, there is an underlying reality that is neither "objective" nor "subjective", but from which both of these realities emerge once a conscious being appears in it. We cannot directly know the true nature of this underlying reality, as it cannot be directly experienced. What we call objective reality is really the experience of the simulation in our mind synthesized from sensory data, as well as our model of this simulation (science), and not the underlying "true" reality.