how does professor Lidenbrock change from the beginning of the book to the end of the book?

Lidenbrock is Axel's uncle and mentor, a man who works as a professor in geology and mineralogy. He is so famous that people come from around the world to attend his lectures. Professor Lidenbrock is hardworking and optimistic, never giving up on the journey to the center of the Earth. He is also stubborn, prideful, and single-minded in his endeavors. After the journey, he becomes even more renowned.