This is a problem which, I think, plagues all sorts of writers - I know I, for one, get that "Oh god, this is rubbish, delete it and never touch it again" feeling at the three quarter point.By now you're probably ready to give up. You're past that first fine furious rapture when every character and idea is new and entertaining. You're not yet at the momentous downhill slide to the end, when words and images tumble out of your head sometimes faster than you can get them down on paper. You're in the middle, a little past the half-way point. The glamour has faded, the magic has gone, your back hurts from all the typing, your family, friends and random email acquaintances have gone from being encouraging or at least accepting to now complaining that they never see you any more---and that even when they do you're preoccupied and no fun. You don't know why you started your novel, you no longer remember why you imagined that anyone would want to read it, and you're pretty sure that even if you finish it it won't have been worth the time or energy and every time you stop long enough to compare it to the thing that you had in your head when you began---a glittering, brilliant, wonderful novel, in which every word spits fire and burns, a book as good or better than the best book you ever read---it falls so painfully short that you're pretty sure that it would be a mercy simply to delete the whole thing.
Welcome to the club.
That's how novels get written.
If you find that you do have this problem, I suggest you have a read of this short article by Neil Gaiman. A very interesting read!
What're your methods for getting past the three quarters done point, in modding or other writing?
