20 years later?

Do you remember "Mr. D."? I mean "my" Mr. D.:

no, Mr. D., I won't dance with you today
just watch me bouncing 'round, and listen what I say
Mr. D., I won't dance with you today
no, Mr. D., I won't dance with you today

In the second verse it says:

how about an agreement, you could
come back in, say, twenty years

Well, the lyrics I put down today - after dreaming them(!) - could be seen as follow-up lyrics, say, 20 years later:

I saw this man
who cast no shadow
and no reflections
in window panes

I double-checked
just to make sure
but each time
it was the same

who is he?
what does it mean?
can he be seen
by other people
or only me?

one day I died
quite suddenly
a heart attack
(that) did me in

to my regret
there was no time
for Goodbyes
with friends and kin

a man reached out to me
a man I thought I'd seen before
"Don't you remember me?
You're the one I've waited for"

who is he?
what does it mean?
can he be seen
by other people
or only me?

Must have been my appointment with the dentist that brought up such thoughts ...