This happened when I was still working as a bookkeeper in a Pasig-based franchising firm.  The year was 1996 when cellular phones were as big and heavy as a red brick and WordStar was still widely used word processing software. 

A newly-hired employee approached me and asked if he can use my PC to access our network printer.  He said his own PC failed to boot.  I said okay but I had a deadline to beat so he better work fast.  "Don't worry.  I've already finished encoding and saved the files here in my hard disk yesterday", he replied. I thought that I didn't hear his response clearly so I asked him, "Where did you say you saved your files?". "Here in my hard disk", he replied while pointing to his brown envelop.  Still puzzled, I stood up to let him use my PC.  Wasting no time, he pulled out a 3 ½" 1.44 MB floppy disk among the 5 ¼" diskettes inside the envelope and inserted it into the drive. 

The case of the mysterious 'hard disk' solved.