Maximizing Brain Potential

Is it true that the brain wants to give you what it thinks you want, as mentioned in the episode The Mind-Blowing Science of Manifestation with Neuroscientist Dr. Tara Swart and the clip Power of Visualization? For example, if after a trauma or negative experience you say you can't visualize your goals anymore and stop trying, does your brain show you the fear and reasons why "you can't visualize" when you try again and it seems difficult? If you insist and tell your brain exactly what you want to see—like visualizing yourself walking—will the brain start to respond to your commands? Are clear instructions really efficient for the brain?