Timon departs from Athens, leaving the lords wondering if he has gone mad, the only explanation they can come up with to explain how he served stones for dinner. Clearly none of the lords have learned anything from Timon's fate; they have not seen that Timon was generous to them though they didn't pay him back in kind, they are blind to their unjust treatment of him, and they cannot see beyond their obsessive need to hold onto their cash.
Timon, however, has undergone a transformation. It was foolish for him to have been so generous with his bounty without considering if or when it would run out, but he did so out of a genuine feeling of kindness to his perceived friends, a desire to share his wealth, and a belief that others would do the same for him. If he took pleasure in giving to his friends who were in need, then surely his own friends would do the same for him. But he learned, in a lightning-fast lesson, that his friends were not so noble-minded as he. But there is no middle ground for Timon; from being a generous kind man, he metamorphoses into a rage-filled misanthrope, and departs for the woods to live as a hermit.
Shakespeare's heroes usually most go through a journey of self-discovery, from a state without self- awareness to one of understanding. Timon foolishly misconceived the power of his wealth, thinking he could freely share it with his friends, but that no one was likely to take advantage of him or pretend to be his friend merely to gain wealth. When he learns that he mismanaged his bounty, and his friends will not help him, he is forced to learn things about greed and ingratitude that he never imagined. Yet his extreme reaction, turning from kindness to hatred, from friendliness to exile, is an unusual learning process, more severe than merely coming to self-knowledge. Timon may learn too much too fast to be able to truly process it and to grow, as all Shakespeare's heroes must. He becomes the opposite of what he was--but is that the same as growing? In this way Timon is an unusual hero, coming to hatred and anger rather than to understanding.