After-Editing-Enlightened Phase

You know how you can tell when you've written something worthwhile? After you've done a billion edits and it's near-perfect, you usually think to yourself: Yay! I've finished, now I get to start on something else.

But sometimes you don't think that.

Instead you think: Oh, I'm really going to miss that character.

You want to go back and relive the excitement you felt when you wrote your first draft. You want to somehow turn that short story into a novel so you can play with characters and cause additional chaos to their once-normal lives. You wish so-and-so hadn't been killed, so they could come back in a sequel. You mourn them like they're real people.

And that's when you know you've written something worthwhile.

So, the question of the evening is...if you love a story so much (short stories as example) is it alright to go back and continue it? What if it's perfect as a stand-alone piece? But you're still aching to write more. Do short stories series work? What about a prelude?

Or is it better just to take the spirit of that story and put it into your next story/novel?

Right now, I'm having problems letting go of a recent short story I wrote. I love it so much, I can't stop thinking about when I work on other stuff.