You write text, decide not to post it, delete it, yet still keeps appearing

[squeezewax]

I thought i'd start a thread, wrote a few paragraphs but then decided not to post it, deleted all the text, and thought it was gone.
A little later i decided to create a new, different, thread. Clicked on 'post new thread' expecting the box to be blank, but all the text i previously wrote was still there, even tho' i deleted it at the time.
I then took ages holding down the backspace key on my keyboard, and got rid of all the text.
Later i clicked on 'post new thread' again, and it was there once more! So i gave up!

How does a person delete something that wasn't even posted?
Thanks.

 

[Kaybee]

Assuming on desktop (could be the same on mobile, not sure):

There is a button with a floppy disc called "Drafts", if you click on it there should be an option that pops up that says "Delete Draft" which should permanently delete what you had typed before. This also works for responses in current threads