With 50 million neurons and several hundred kilometers of axons terminating in almost one trillion synapses for every cubic centimeter, and consuming only about 12 watts energy for the entire cortex, the brain is arguably one of the most complex and densely packed, yet highly efficient information processing systems known. It is also the seat of sensory perception, memory, and the self - in short, what makes us humans to humans. On the other hand, while classical physics assumed a logical separation between external physical objects and observing subject, quantum mechanical interpretations seem to suggest a counterintuitive entanglement between the object and the self which observes the very object. In this talk I will sketch out what modern neuroscience can teach us about what (and how) the brain knows about the world, and proceed to speculate what the interplay between physics and brain can tell us about the fundamental fabric of reality.