This is a lovely, moving interpretation. You lead us to the realization slowly of the tragic circumstance of Nielson's consciousness. So many issues are implicit in this story...the idea of who we are, and what is the essence of awareness. What is real and not real about the present and about our perceptions.
Some great literature has explored the same dilemma.
You did a good job...the essence of Nielson's tragedy is effectively captured by the one "lone" tear that rolls down his cheek.