Subway Reading Hazards

Once, when I was on the subway, I was writing a long letter a some woman
I was in love with -- I can't even remember who she was now.  Anyway,
as I was writing, I noticed the little kid sitting next to me was reading what
I was writing.  I was mildly irritated by this, so I finished the sentence I was
writing, and then drew a picture of two people sitting in a seat -- one
was obviously the kid, and the other was a very crude representation of
myself.  The kid was looking at what I was writing.  Next to the kid was this
huge monster, with gigantic fangs, about to bite the kid's head off.  The
caption I wrote under the picture was:

"Reading another person's letters as they write them can be hazardous to
your health.  You might be too absorbed to see the monster that's about to
eat you."