Am i that stupid ?

Maybe, maybe not.  You may need to check some stuff first before doing this conclusion. Also, you should read this doc from

<?php   echo("type: " . $_SERVER['content_type']);   var_dump(file_get_contents('php://input'));   var_dump($_POST); ?>
If you want to submitting forms with files or data containing non-ASCII characters, keep in mind you should use the content type : multipart/form-data. By default, it's using application/x-www-form-urlencoded. If you want more information about multipart/form-data, you should read RFC2388
If you got content from php://input but not into $_POST , it may coming from your php.ini file. Check post_max_size if you got a valid value.
You may also check out your html file and you don't have duplicate "name" and also a name attribute. If you forget the "name" attribute, the field will not be sent.