This little demo in the debugger (without strict) should make it clearer

  DB<5> print "x".NAME                    # bareword treated as string
xNAME
  DB<6> sub NAME {42}                     # sub declaration

  DB<7> print "x".NAME                    # bareword now known to be s
+ub
x42
  DB<8> print "x".NAME2()                 # explicit sub call 
Undefined subroutine &main::NAME2 called at (eval 17)[C:/Perl_524/lib/
+perl5db.pl:737] line 2.

  DB<9> print "x".&NAME2                  # explicit sub call 
Undefined subroutine &main::NAME2 called at (eval 18)[C:/Perl_524/lib/
+perl5db.pl:737] line 2.

  DB<10>
[download]