Final answer:
In 'Gifted Hands: The Ben Carson Story,' Denise's surgery serves as a realization for Ben Carson that knowing one's purpose and performing capably are essential, irrespective of external skepticism.
Step-by-step explanation:
In the book 'Gifted Hands: The Ben Carson Story,' Denise's surgery confirmed for Ben Carson that when people know their purpose and they know their job, it doesn't matter who questions them. This means that when individuals have a clear understanding of their goals and are competent in their work, they can overcome challenges and succeed regardless of others' doubts or criticisms.