How does the lawyer spend his 15 years of imprisonment in "The Bet" by Anton Checkhov?

The impulsive
lawyer is sequestered in the banker's lodge where he can have virtually anything he desires
except human companionship.

After arguing against the banker that life
imprisonment is not less humane than capital punishment--"to live anyhow is better than not
at all"--the banker wages two million rubles that the lawyer cannot stay in solitary
confinement for five years. With the arrogance and recklessness of youth, the lawyer contends
that he can stay, not just five, but fifteen years. The banker accepts the bet, but he warns the
younger man,

Don't forget either, you unhappy man, that
voluntary confinement is a great deal harder to bear than compulsory. 

So, while the lawyer tries to prove that living an isolated life is
not a hardship and win the bet of two million, he can have any of the books he wants, he is
given a piano and music, he is allowed to write letters, and he may drink wine and smoke. The
only outlet to the outside is a little window through which the books and letters and other
things are passed. 

During the first year, the prisoner is extremely lonely;
he spends a great deal of time at the piano. Because he is lonely, he refuses the wine and
tobacco; in explanation, he writes that wine stimulates the senses, only exacerbating his lonely
condition. Tobacco ruins the air of his little room.
In the second year, the prisoner
stops playing the piano, and he exchanges the light reading of his first year for the classics.
Then, in his fifth year, the prisoner requests wine, and he again plays the piano. During this
year, the lawyer mostly eats and drink and lies on his bed. But, at times he writes all night;
afterwards, however, he tears up what he has written, crying. 
Then, in the sixth year,
he begins to study languages, history, and philosophy. He immerses himself in these studies so
much that the banker is overwhelmed as he tries to furnish the books. After the lawyer learns
six languages, the prisoner writes his jailer in these languages; further, he requests that the
banker show them to experts and fire a shot in his garden if they are correct. The banker
follows the lawyer's instructions and fires two shots. Hearing these shots, the lawyer expresses
his happiness since he has mastered six hundred volumes of scholarly learning.
After
the tenth year, the lawyer abandons all reading, but the Gospels. Theology and philosophy are
his next readings. In the last two years of his confinement, the lawyer reads indiscriminately,
choosing Shakespeare, then a medical manual, then philosophy or theology.

His reading suggested a man in the sea among the wreckage of his
ship and trying to save his life by greedily clutching first at one spar, and then at
another.

Before he is released, the lawyer, now a man of
despair, writes that he despises freedom, life, and health--all that is called "the good
things of the world."