Text: Charles W. Kent (notes) Robert A. Stewart (variants) (ed. J. A. Harrison), “Notes to Dreams,” The Complete Works of Edgar Allan Poe — Vol. VII: Poems (1902), 7:148

[page 148:]

Oh! that my young life were a lasting dream, for dreams of living light and loveliness are no less than Heaven. Such a moment he had once, but a power or spell came over him. “I have been happy” even though in a past dream fuller of reality than hope has known.

Note the unhappy awakening from a dream of bliss with no hope of regaining the lost hour.