What is The Connection Between Sleeping and Dying

In "Richard Cory" by Edwin Arlington Robinson he makes a bold statement.  The statement that he makes is that everyone has struggles rich, poor young or old.  That everyone has demons to deal with.  I think that this says a lot about hapiness in general.  As even the peasants struggling for bread were much more happy than Richard Cory.  I see a connection in his death and in others ignorace or sleeping.  As he knew so much more yet it meant nothing to him.  As well there is this deep connection that regardless of class or looks there is an internal sleeping struggle within every soul.  This struggle could be depression or a habit yet I believe this poem morbidly proves that its not always easier from someone else's perspective.  From this poem we can learn not to judge as we never know what someone has been through or had to experience in their life.