Sometimes (not always, unfortunately), when I click the "Back" button in my browser, I do get a lost post back.

At least once, I've had the electricity in the neighborhood go out for an hour and still been able to get the post back. Sometimes Firefox just asks if I want to restore the previous session and when I click "Yes", there it is. Other times I've had to put the cursor in the box (now empty) where I'd been writing the post, right-click, and select "Undo".