In your job search and in your life--attitude is EVERYTHING.
If you think you can, you have the mental strength to deal with obstacles and setbacks, and makes you a little braver than you might otherwise be, so you tackle goals that are bigger than you might otherwise tackle.
If you think you can't, you've already given up.
Forbes has a list of wonderful Henry Ford quotes:
21 Quotes From Henry Ford On Business, Leadership And Life
If you need a mental strength boost, set up a Career Coaching session with me: Peggy McKee Career Coaching. I'd love to help you.
Best of luck!