Problem Draft Disappearance

I used the save draft button, to save a draft of a thread I wanted to create.
After searching extensively on this site to find where drafts are saved, i couldn't find it.
Instead, I found that even closing and opening my browser loaded my unfinished new thread and thought that was the work of the button.
Now it's gone. I believe it was just the browser temporalilly saving my thread.
It was a thread in pc hardware help.

Where are the drafts saved? How can I find my draft? Could it be on some obscure broswer cache file on my hard drive?

EDIT: Just to clarify, the draft button is one you see on the embedded toolbar when you try to make a new post. It's close to the right and is a floppy disk, much like most save buttons. It gives the options of saving and deleteing drafts, not loading however, which is pretty strange.