Why doesn't Perl file glob() work outside of a loop in scalar context?

Question

According to the Perl documentation on file globbing, the <*> operator or glob() function, when used in a scalar context, should iterate through the list of files matching

Answer 1

The following code also seems to create 2 separate instances of the iterator...

for ( 1..3 )
{
   $filename = <*>;
   print "$filename\n" if defined $filename;
   $filename = <*>;
   print "$filename\n" if defined $filename;
}

I guess I see the logic there, but it is kind of counter intuitive and contradictory to the documentation. The docs don't mention anything about having to be in a loop for the iteration to work.