What I don't understand is why japhy's example works. I would expect that it would try to glob (john jacob jingleheimer schmidt), not see anything like that in the directory, and evaluate to nothing.

glob() either mimics the shell or delegates to it for pattern expansion. Consider the difference between

  % echo foo
  foo
  %
[download]

and

  % echo foo*
  echo: No match.
  %
[download]

when there are no files begining with "foo" in the current directory.