Hi David, thanks for your comment! I agree with you, I just think we're talking about different things.

You're absolutely right, in terms of professional achievements, there are many factors other than a can-do attitude that will affect what we can achieve.

I'm talking specifically about behaviour here. How we behave is the one thing which is completely in our own hands. I think people are often encouraged to believe that who they are (in terms of character) is set in stone, and it's that idea that I'm arguing against here.