In visions of the dark night I have dreamed of joy departed-- But a waking dream of life and light Hath left me broken-hearted.

Ceux qui revent eveilles ont conscience de 1000 choses qui echapent a ceux qui ne revent qu'endormis. The one who has day dream are aware of 1000 things that the one who dreams only when he sleeps will never understand. (it sounds better in french, I do what I can with my translation...)

You are not wrong who deem That my days have been a dream; 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.