You can do anything you think you can. This knowledge is literally the gift of the gods, for through it you can solve every human problem. It should make of you an incurable optimist. It is the open door.

Collier frames belief in one’s own capacity as a practical, almost sacred force: the conviction “I can” becomes the lever that moves action, persistence, and ingenuity. The line does not claim that wishing guarantees outcomes; rather, it argues that self-conception sets the limits of effort and imagination. Calling it a “gift of the gods” elevates confidence from mere mood to a foundational human tool—an inner permission that unlocks problem‑solving. The “incurable optimist” is someone who, armed with this principle, treats obstacles as solvable and setbacks as temporary. The “open door” metaphor suggests access: belief is the threshold that turns possibility into attempt.