--- title: "Knowing When to Stop" description: "Persisting is a virtue right up to the point where the evidence has arrived and been ignored. Deciding in advance what result would make you stop is how you tell one from the other later." canonical: https://lightmysky.com/learn/life-skills/knowing-when-to-stop-mt_Xh61d76aET source: https://lightmysky.com/learn/life-skills/knowing-when-to-stop-mt_Xh61d76aET.md retrieved: 2026-09-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Knowing When to Stop Persisting is a virtue right up to the point where the evidence has arrived and been ignored. Deciding in advance what result would make you stop is how you tell one from the other later. Subject: Life Skills · Area: Entrepreneurship · Ages 16 to 18 Page: https://lightmysky.com/learn/life-skills/knowing-when-to-stop-mt_Xh61d76aET ## Ready when they can - Write down in advance what result would make you close the venture - Explain how money and time already spent should not affect the decision, and why they usually do - Say what is worth keeping from a project that ends ## Lesson: Decide your stop rule before you start Persisting is a virtue right up to the point where the evidence has arrived and been ignored. Every founder should write down a stop rule before starting: the result that ends the project, for example no paying customers after six months or costs above an agreed limit. Deciding early matters because once you are tired and proud, every bad month looks like one more month to try. A written rule turns a painful moment into a promise you already made. **Example.** You run a weekend market stall. Your stop rule says you quit if the next month cannot plausibly cover its own costs. Month five is bad, and pride whispers to continue. You compare only what comes next, future cost against future return, and the numbers fail. You close with pride intact, because the decision was made months ago by a calmer you. Money already spent is gone whether you quit or carry on. That is what sunk means: last term's rent and the weekends building a stall nobody visits never come back. The common trap is paying more just to justify what you paid before. Ignore it. In the short run the rule is simple too: keep going only if sales cover the costs that stop when you stop, like ingredients and hourly wages. If each sale loses on those alone, selling more only digs deeper. **Tip.** Remember what stopping buys and what survives. Stopping on time frees your cash, your evenings and your attention for the next idea, and it leaves your reputation intact. Also price every hour: a Saturday restocking a failing stall is a Saturday not spent on a part-time job, revision or a better venture. If an alternative beats the project, the project costs you even in weeks it breaks even. Keep the records and lessons, since they become judgment for the next attempt. **Recap.** Write the stop line early, ignore sunk costs, and honour the rule. ## Practice 8 questions on this page, each with its working shown. ## Needs first - [Learning from Failure](https://lightmysky.com/learn/life-skills/learning-from-failure-mt_dknMcCqvoY) - [Unit Economics: Does Each Sale Make Money?](https://lightmysky.com/learn/life-skills/unit-economics-does-each-sale-make-money-mt_NUoV6LB-o4) - [The Smallest Version Worth Testing](https://lightmysky.com/learn/life-skills/the-smallest-version-worth-testing-mt_q7e_4e7BoN)