In "The Bet" what did each the banker and the lawyer learn about life?

Before the application of the bet, the banker had argued that life in prison was worse than capital punishment (death). The lawyer argued that death was clearly worse. To prove that imprisonment is tolerable, the lawyer agrees to live in the banker's garden house for fifteen years. His reward, if he succeeds, is two million rubles. Upon the final day before the fifteen years is up, the banker knows he will be ruined if he pays the two million rubles. So, he schemes to kill his captive (the lawyer) while shifting the blame of the murder on to the watchman. At this point, the banker has learned nothing. His only intention is to kill the lawyer and protect his money.

When he goes to kill him, the lawyer is asleep and there is a note on the table. Here are some excerpts from the lawyer's note to the banker: 

With a clear conscience I tell you, as before God, who beholds me, that I despise freedom and life and health and all that your good books call the good things of the world. 

Your books have given me wisdom. All that the unresting thought of man has created in the ages is compressed into a small compass in my brain. I am wiser than all of you. 

The lawyer also writes that he will leave his cell five minutes early and thus forfeit the bet. He has achieved some kind of wisdom and now he does not want the money. The lawyer seems bitter but enlightened. Of books and blessings of the world, the lawyer writes, "It is all worthless, fleeting, illusory, and deceptive, like a mirage." After living in books and in his imagination for fifteen years, he has come to the conclusion that life is fleeting and an illusion. Perhaps he is saying that the "real" world is as illusory as his imagination. Therefore money is as meaningless in the real world as it is in his mind. 

Upon reading this, the banker kisses the lawyer's head and cries in contempt of himself. He hates himself for valuing his money over the lawyer's life and putting the lawyer through such an ordeal. Here, the banker seems to have learned something about the corruption of greed.