What Did the lawyer feel that he gained from his fifteen years of solitary confinement In the bet?

In Anton Chekhov's short story "The Bet," the lawyer feels that his fifteen years of solitary confinement provided him with profound insights into life and human existence. He gains a deep understanding of knowledge and wisdom, realizing that material wealth and societal norms hold little value compared to the pursuit of enlightenment. Ultimately, he rejects the monetary prize, feeling that he has transcended the superficiality of the world outside and recognizing the futility of his previous desires.