Our discussion of dreams reminded me of Langston Hughes’ poem Harlem, about what will happen to a dream if it is postponed too long.
What happens to a dream deferred?
      Does it dry up
      like a raisin in the sun?
      Or fester like a sore—
      And then run?
      Does it stink like rotten meat?
      Or crust and sugar over—
      like a syrupy sweet?
      Maybe it just sags
      like a heavy load.
      Or does it explode?
Hughes answers his first rhetorical question with five other questions. If a dream is left alone too long it will dry up.  It may shrivel like a grape, once green and nutritious, left out in the sun. He conveys the idea that if your talents are neglected they may dry out and leave you unnourished. An uncompleted dream may cause you pain like a nagging wound that won’t heal. Hughes emphasizes the grotesque idea that  a dream, left alone, will decay. In startling contrast to this comparison, Hughes suggests that a dream is like a sugary substance. That it is sweet, tantalizing even, but can easily crust over and become stale. He states that dreams can weigh you down. Lastly he says, a dream can explode, like a bomb, or an ultimate act of violence, after which nothing can be salvaged.
Caliban’s attempt to murder Prospero and take over the island clearly represents an “explosion” catalyzed by a dream deferred. Prospero’s revenge is another manifestation of a forestalled goal. He becomes tainted by it, manipulating other men to exact his revenge, becoming no better than those who betrayed him– crusting over, rotting, festering.