sub foo; *{-1} = sub { 'oh' }; # Create a sub called "-1". print &{-1}(); # "oh" *bar = $::{foo}; # Really? print defined &bar; # "1" Huh? So now &bar is defined # even though &foo isn't? print bar(); # "oh" #$foo; # But all this would change if you # uncommented "$foo;".