He doesn't dream anymore, exhaustion far too great to allow even a hint of a dream. A blessing in disguise, for what dreams could occur in war other than nightmares? Asleep and awake, quick and simple. No interruptions to his subconscious, no talking in his sleep to a figure no one else can see, nothing except the morning (or evening or night or afternoon) call of duty.
Korea has washed away all dreams, leaving him alive in a nightmare. Yes, a blessing in disguise.
He wishes, sometimes, that the dreams would come -- perhaps then he could remember her face.