You've stumbled on one of life's uncertainties. When should you abandon something, when should you persevere? Sunk cost says that "how much you've already spen

You've stumbled on one of life's uncertainties. When should you abandon something, when should you persevere? Sunk cost says that "how much you've already spent" is not a factor. And whole you certainly shouldn't make it a factor, it certainly makes the "decision" harder. It's easier to abandon a project you've spent a weekend on, than one you've spent a year on. You can try thinking of it objectively. "Here's this project, someone else did. Do you want to take it over, and run with it?" Did you do your market research first? Do you have some deposits in the bank for when it is done? Are you quitting because there's more work to do? Or because you've taken it to market, and there is no market...?