Amateurs believe that the world should work the way they want it to.
Professionals realize that they have to work with the world as they find it.
Amateurs are scared of uncertainty and avoid surprises.
Professionals feel like they are capable of handling almost anything and embrace surprises.
Amateurs think they have all the answers.
Professionals know they will never have all the answers.
Amateurs are arrogant.
Professionals are confident.