Buddhists say that thoughts are like drops of water on the brain; when you reinforce the same thought, it will etch a new stream into your consciousness, like water eroding the side of a mountain. Scientists confirm this bit of folk wisdom: our neurons break connections and form new pathways all the time. Even if you’ve been programmed to fear death, that particular pathway isn’t set in stone. Each of us is responsible for seeking out new knowledge and creating new mental circuits.