Go stand in front of a mirror. Look into your eyes. Straight into your eyes and think. Think about what you desire the most. Something that would not let you die in peace if left unachieved, unattained.
Can you do it? For how long can you keep staring at yourself? Directly in the eye.
You see yourself naked. All your flaws in front of you. Every sliver out of line. Self doubt prevails.
Conquer it and you would have tamed the brain.
Tame the brain and you would have tamed the universe.