Every writer I know (and all of the ones I don't) has at least one, and usually about 27 pieces going at any one time. First draft, fifth draft, critiqued, still hidden away from humanity, submitted half a dozen times.
The WIP collection is like your underwear collection. Some are holey and have sprung elastic but are so comfortable that you can't give up on them yet. Your SO saw them back when they were new, but now you keep them for yourself. Others are fancy, special, their color not washed out and faded from too many washings. They give you that tingly feeling and you want to share them with that special someone.
Just as it takes a while to know which knickers work well under which clothes and which just. don't. fit. right. and make you fidget, it takes a while to get to know your stories. And sharing them before they're right? It kills the buzz, just like sharing that fabulous matching black satin set with the lacing before you figure out how it works, how to put it on and, more important, how to take it off without swaying like a sailor on board a ship and tripping over your own feet. Not sexy.
OK, this whole WIP as underwear metaphor is getting a little silly.
I'm one of those writers who doesn't know what the hell I'm doing until the third draft, if I'm lucky. Talking about a story opens this door to the world that says "Hey, help me figure this story out." Only, I'm not so keen on getting that kind of 'help'. It muddies things. It turns into a "what about this idea?" free-for-all.
So I try to keep my mouth shut for the most part. And I'm picky about who I tell what to. A painter doesn't show a new piece to the whole world after every brushstroke, so why would a writer do it?
Treat WIPs like sourdough starter. Feed them. Keep them warm. And keep the damn lid on until they're ready to bake!