You think this is going to be me telling you how I've quit editing my novel again, because it's complete and utter shit. But it isn't [about that]! Novel editing continues apace, I'm about three quarters of the way through. I think I'll have increased the word count by about 25% in the process. Not sure how that happened...
ANYWAY, no, this is not about that, exactly, but it is about the virtue of quitting. I was listening to this Freakonomics podcast, about quitting and it struck a chord, largely because it was saying that quitting is a Good Thing. Admittedly, they meant like if you're in a bad job, or you're a prostitute, or something, but it works with all walks of life, including in literature.
Hope Clark wrote a little blog post about quitting books, recently, where she says that when she's reading, she'll give a book 75 pages to interest her and if it doesn't, she'll stop. That's what I do! Though I will, generously, give it 100 pages. If it doesn't entertain me, or at least make me feel things, I get rid of it, and still, crucially, feel entitled to have an opinion on it.
I know a lot of people who will not abandon a book. It might mean that they barely read anymore, or they don't enjoy reading anymore, but they will finish that book, and they get a bit upset when you say you didn't like something so you stopped reading it. There are, sometimes, insinuations... but whatever; in the time it took them to read that book, I read three others, and they were great.
This works with writing too, obviously. If an idea is not working, you should probably just give it up, and move on to something else. Maybe the idea just wasn't very good in the first place, or maybe it will be good one day, but not right now, with where you are as a writer/human being. It doesn't make you a bad person. There are loads of other things you can do!
And that is the crux-a-mundo. When you're reading a book you don't enjoy, you read much less than normal. If you're writing something that is not working, and is painful to write, you'll be writing less often that you usually do. Which is not a good thing. To keep it interesting (if not necessarily fun), you really do need to know when to cut your losses, however painful it might feel.
I'm assuming here that you're a slightly obsessive type of person who finds it hard to quit things, or to leave food on your plate. Waste is bad, I agree, but giving something up is not waste. We only have so much time to play with, and you waste it when you don't enjoy your leisure time.