I may be losing my mind. I swear I've been able to use something like
PHP Code:
include("/file.php"); 
And it would grab file.php located in the document root no matter where that line of code was in the directory structure. But for the life of me I can't find an environment that respects that.

I know there are a bizillion functions available on php.net for setting $_SERVER['document_root'] but I was hoping to avoid that by using the almighty single '/'.

Am I losing my mind?