I've read a lot of advice telling aspiring writers to never give up on a story. I understand this advice, and generally it's pretty good. It's easy to get bored while writing something, especially if it's a long work like a novel. No matter how awesome your idea is, no matter how exciting your plot is, after awhile you're just going to get bored and want to do something else.
Ideas don't stop coming just because you're writing. Hell, if anything, ideas come faster when you're writing. It's extremely easy to lose track of what you're working on, simply because it's less interesting than the great new idea you just had.
Of course, the story you're working on was a great new idea last week, wasn't it? When you first had it? The idea just popped into your head, and you fell in absolute love with it. Maybe you even stopped writing what you were working on at the time to give this great new idea the attention it deserved! But now that you're a few days into writing it (or a few weeks, or a few months), you've started to run head-on into the part that's called "hard work." That part's not as exciting.
This brand new idea, though, wow! You can already tell that one will just flow right out of you! You'll probably be able to bang out a first draft in a day!
Is that possible? Enh. Technically.
It's more possible that you're going to end up doing this for fifteen stories in a row, leaving each one half-finished as you move on to what you know will really be good, this time.
Failure to stick with a story just because it's become a slog is probably one of the biggest reasons people fail to write at all. I've done that. I've done that a lot.
So now how am I going to say that I disagree with the statement "never give up?" Well, it's a qualified disagreement. Let me give the example of a crime story I've been working on for the past month and a half. For some reason, the story just won't work. I don't know exactly why, either. I've got the ending written, and the beginning. I've got most of the middle done. But there's a heist right at the center of the story that I, apparently, cannot write. Not right now, at least. I've spend the last three weeks on this story, trying to write this thing, and I can't do it.
That's a signal, I think. I like this story, and I need to come back to it later. But for right now, it's doing nothing but keeping me from working. There's only so many times I can sit down, look at the same story, and fail, before I just start to hate myself.
Meanwhile, I've had another idea (or six) dancing around in my head this whole time. So tonight I actually did manage to bang out most of a first draft of one of those stories. After I finish this one, I'll come back to the heist and see if anything any clearer. A fresh mind can do a lot to get past a roadblock.