When running the following code, the filenames of all files below C:\Test are printed. Why doesn't it print just Hello (n times, depending on how many files are processed)?

Does this imply that I cannot rely on shift to reliably assign to $_? Imagine a coworker implements the wtf function and doesn't know that it's called from a File::Find wanted sub.

I run this code with Strawberry Perl 5.12

use strict;
use warnings;

use File::Find;

find(\&wanted, "C:\\test");

sub wanted{
    wtf("Hello");
}

sub wtf {
    shift;
    print; #expecting Hello 
}