He who can, does. He who cannot, teaches. If you have an apple and I have an apple and we exchange these apples then you and I will still each have one apple. But if you have an idea and I have an idea and we exchange these ideas, then each of us will have two ideas. Reasonable people adapt themselves to the world.
Unreasonable people attempt to adapt the world to themselves.
All progress, therefore, depends on unreasonable people. Success does not consist in never making mistakes but in never making the same one a second time. The power of accurate observation is commonly called cynicism by those who have not got it. Liberty means responsibility. That is why most men dread it.