How do we see the theme of adversity in As You Like It?

Sweet are the uses of adversity; Which, like the toad, ugly and venomous, Wears yet a precious jewel in his head...
This is a profound insight expressed in a striking simile. It happens very often that, as Buddha says, bad fortune can turn into good fortune, and good fortune can turn into bad fortune. There are many possible real-life examples. For instance, a man loses his job, can't pay his bills, loses his house through foreclosure, and has to move to a different city to obtain another job. However, he finds work he likes better and meets people who are more compatible; maybe he even falls in love. He also discovers that he has hidden resources which he might never have realized if he hadn't be forced to stop and think about his life, his values, his ambitions. Some people go back to school and are guided into new careers they hadn't even known existed. Some people commit crimes and are sent to prison, but there they have the time and motivation to think about their lives and to find comfort and guidance through religion. Adversity is something that practically everyone is going to have to experience sooner or later. It is a part of life. It can be overwhelming or it can be rejuvenating. The banished Duke in As You Like It finds himself living in a forest, but there, like the characters in the Upanishads, he discovers that he prefers a life of freedom and meditation to the artificial and hypocritical life of the typical court. Adversity helps us recognize who our friends are--and who our friends aren't.