Say you've written a story in which a driver picks up a mysterious hitchhiker, and in the end there's a surprise twist ending: the hitchhiker turns out to have been dead for years!
Now, I don't advocate writing surprise twist ending stories, especially not ones that bear a suspicious resemblance to well-known urban legends. But if you must write a surprise twist ending story, it seems to me that it behooves you to try to keep the twist ending a surprise.
And that means that it's probably not a good idea to title the above story with a title like "The Hitchhiker Who Was Really Dead Even Though You're Not Supposed to Realize That at First." Or even "The Ghost Hitchhiker."
Every couple of months, we get a story in which the title clearly and directly gives away the surprise twist ending. (The titles are more like my second example than like my first; I was exaggerating for comic effect.) And I always wonder what the author was thinking. It's true that I sometimes don't really register the title of a story until after I finish reading it, but presumably most readers will read the title before they read the story. I suppose it's possible that the author doesn't actually intend the ending to be a surprise--but in the kind of story I'm talking about, the ending is always presented as if the author expects the reader to be surprised, and as if that's the whole point of the story.
And before someone suggests this, I'm pretty certain that none of these stories are intended as metacommentary about the nature of stories, or about surprise twist endings, or anything like that.