The earlier it dies, the cheaper it is.

Learning goal

Define a test or signal that would kill the idea.
Run the test as soon as possible.
Stop investing when the idea fails the test.

Why it matters

Sunk cost grows over time.
Early kill saves resources.
Killing an idea is not personal failure.

Key idea

Kill early means stopping bad or wrong ideas as soon as evidence shows they do not work. Define the kill criterion; run the test; stop investing when it fails.

Common mistakes

Sunk cost: continuing because we already invested.
No clear kill criterion.
Treating killing an idea as personal failure.

Today's move

For one idea or project, write the kill criterion: "We stop if [observable condition]." Decide when you will check it.

Self-check

You can explain the key idea in one sentence.
You have one concrete move to do today.