The most popular current theory about "self-awareness" is named "Bozeman Self-awareness," which is a hypothesis derived from the concept of the Boltzmann brain.
Human observations of a low-entropy world originate from random fluctuations within a high-entropy universe.
Large fluctuations can create a state of very low entropy; although the probability of such low entropy is very slim, it still occurs on the vast scale of the universe.
Further deduction leads to the conclusion: It's possible that these fluctuations could produce a brain, or a self-aware entity, and the likelihood of this happening is much greater than the chances of producing the low-entropy world humans inhabit and evolving a vast number of brains.
It can be calculated that the probability of fluctuations creating the human world is e^(-10^100), while the probability of fluctuating into a Boltzmann brain is e^(-10^28), a difference of over seventy orders of magnitude.