Yet if Hope has flown away
In a night, or in a day,
In a vision, or in none,
Is it therefore the less gone?
All that we see or seem
Is but a dream within a dream.
I stand amid the roar
Of a surf-tormented shore
And I hold within my hand
Grains of the golden sand —
How few! yet how they creep
Through my fingers to the deep,
While I weep — while I weep!
O God! can I not grasp
Them with a tighter clasp?
O God! can I not save
The narrator becomes very sad as he weeps out of the realization that nothing really matters and ultimately makes his life feel worthless because it will all slip away – life the grains of sand creeping through his hands. 
 The repetition of “while I weep” serves to reinforce the fact that he is losing all of his happiness.  He cannot seem to cope with the changing aspect of life because it doesn’t work out in his favor.  The first instance of “while I weep” sets the scene for him crying, but the second emphasizes the importance of his incapability to do anything to help himself but sob. 
 The water from his tears just as much reflects his depression as it does continue washing away sand from his hands. 
 
 
 The line says a lot about Poe’s style of writing, marked by intense horror, sadness and darkness. Psychologists have good reason to  believe he suffered from depression, among other psychological conditions . 
 When describing Poe in terms of the Five-Factor Model of personality we can conclude that he would be high on Neuroticism – evident by the constant nervous anxiety he was said to have, as well as his melancholy and irritability. Poe would also be described as being low in Agreeableness and Conscientiousness since he was argumentative, untrusting, and lacked self-control (i.e. his drinking, his failure to pursue education).
A Dream Within A Dream