"According to neuroscience, we are a highly and deeply orchestrated symphony of quintillions of different interrelated chemical reactions per second. There are probably over 10 quintillion neuroreceptors in the brain distributed across 500 trillion synapses connecting 100 billion neurons. Each neuroreceptor undergoes possibly 100 chemical reactions per second in which it collides with a signaling molecule and reacts in some way. These also aren’t your usual chemical reactions like you learn in chemistry in which molecules recombine to form new molecules. These are electrostatic interactions in which 3D molecules collide with each other like gears, causing “switches” to open and close. The molecules do not typically bond with each other, but they electrically “stick” to each other for a few milliseconds, causing microscopic 3D shape changes that allow atoms to pass through small openings, for example."
For more insights into the evolution of personal consciousness, the reader is referred
to the Seven Levels of Human Identity, and the Seven Levels of Human Motivation.