Our brain produces a half-cup of fluid every day called cerebrospinal. Our brain floats in this bath of cerebrospinal fluid which acts as a shock absorber to keep the brain from being crushed by its weight.
The brains of introverts and extroverts persons are measurably different. MRIs reports reveal that the dopamine reward network is more active in the brains of extrovert persons while introverts' person brains have more gray matter.
Our 95% of decisions take place in your subconscious.