You are three years into a career you hate. You've already invested too much to quit now. You're 200 pages into a terrible book. You might as well finish it. You've spent $40,000 on a startup that isn't working. You keep going because you can't write off the loss.
This is the Sunk Cost Fallacy — one of the most expensive mental errors humans make.
The Mechanics
A sunk cost is any cost (time, money, energy) that has already been paid and cannot be recovered. The rational approach is to ignore sunk costs entirely when making future decisions — because they are gone regardless of what you do next.
But human psychology doesn't work rationally. Loss aversion and the pain of "wasted" investment hijack logical decision-making. We keep betting on losing positions to justify what we've already lost.
The Real Cost of Sunk Costs
Every day you stay in a losing position because of what you've invested is a day you're not investing in something that could win. The sunk cost isn't just money you've lost — it's the opportunity cost of everything you could be doing instead.
The mathematician's framing: The question is never "How much have I put in?" The question is always "Given where I am right now, what's the best next move?"
How to Escape the Trap
The Zero-Day Reset: Imagine you're making this decision for the first time today, with no history. Would you start this project? Take this job? Stay in this relationship? If the answer is no — that's your answer.
The Advisor Test: What would you tell a friend in your exact situation if they had no prior investment? Give yourself the same advice.
The Asymmetry Check: Is the potential upside from continuing actually worth the future cost? Not the past cost — the future cost.
Takeaway
The past doesn't vote on your future. Cut the losing bet. Redeploy the resources. The CogniScroll Feed has more decision-making frameworks to protect your future self.