Hahaha, well, greet is a string constant. Its is not a variable

Why is that significant? Is the following code different somehow?

use strict;
use warnings;
use 5.010;

sub greet {
    say 'hello';
}

sub test {
    my $str = "greet";
    goto &{$str}; #SYMBOLIC REFERENCE
}

test();
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I'm still dereferencing something that is not a hard reference, {$str}, ergo according to "Programming Perl" the "value" is a symbolic reference. And it's my understanding that the only way perl can find the greet() subroutine is by looking in the symbol table--because the string 'greet' does not point to a subroutine somewhere in memory.