Acharya Prashant explains that the human body and brain function through 'muscle memory,' which retains past habits, genetic material, and centuries of evolutionary history. While consciousness can change instantly, like solving a mathematical problem or switching on a light, the physical body and its deep-seated patterns take significant time to transform. He emphasizes that the past is literally stored in the body's wiring and electrical signals, and one must patiently endure the lingering effects of old tendencies rather than expecting them to vanish immediately. The key to dealing with these old impressions is to keep oneself so occupied with meaningful work that there is minimal time left for the past to resurface.