In case you are wondering ... just suppose you are preparing to send an email to someone... anyone ... and you are adding an attachment.  You have nothing on your desktop screen ... no icons of any kind just the attachment you are sending.

You add it to your email BUT, you have to open it just in case you are sending anything else (that may be secret).  It is the correct attachment and you hit send.  AND YES, you are an OCD Leaner ... (welcome to the club)