Your brain controls you a lot. It speaks faster than your mouth. It lets you do things possible. Makes you move and analyzed. In deed, the brain is one of the useful organs found in a human body. Without it, you can never live.
Despite of having a brain, it sometimes cross over a certain person's mind the thing we call doubt.
Doubt makes a certain decision not vivid. It crashes you down. It lies not beyond trust. It can fall to false mistake. Can get you carried away. It bugs your mind and makes you awake for all times.
It sometimes interferes decision making. It's like a corrosive material that slowly destructs your attention and concentration. Makes you feel cold.
What an anxiety this word doubt brings. So think properly without doubts. Accept failures cause that's one way how a certain person becomes a successful individual. Learn.... learn.... and learn...