“Test Your Brain” from the documentary that shown at National Geography is full of mind tricks. It want to show us about brain, and how its work. Some trick that had been shown sometimes it’s not logically, but it’s true because the tricks use the play of mind. For example, test your brain that show when the wallet, scarf, cell phone, and handkerchief had been stolen. The tricks had made the men’s brain to focus to what he did without realize that his thing had been stolen. After that, the trick had been explained by the men, its make an “eureka” moment to the people who saw this documentary. Its shows that our brain is divide by two which is left and right. When the person focus what the men did to him, he cannot realize that his thing had been stolen and when the thing had been given back by the men, it’s become eureka moment to that person. The documentary also shows us that how brain work and its need the full of focus. For example, the replica of brain that shows in every slot of documentary. We don’t realize it’s until it’s explain and show back to us and then it became a “eureka” moment. That is why the focus of brain is very important to us.