fool me once, shame on you; fool me twice, shame on me
Proposed by a contributor, not yet supported by evidence.
Also seen as: Fool me once, shame on you. Fool me twice, shame on me
Sense 1
After being tricked once, one should learn from one's mistakes and avoid being tricked in the same way another time.
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Sense 2
If someone deceives you once, it's their fault, but if they deceive you again, it's yours for trusting them again.
Examples
AI-drafted example auto-approved by rule (illustrative, not a corpus attestation)
Sources & notes
Listed on English Wikiquote “English proverbs” (CC BY-SA 4.0, retrieved 2026-07-31). Definition drafted by AI (@cf/meta/llama-3.3-70b-instruct-fp8-fast) and auto-approved by rule on 2026-07-31; pending editor spot-check.
Common questions
What does “fool me once, shame on you; fool me twice, shame on me” mean?
After being tricked once, one should learn from one's mistakes and avoid being tricked in the same way another time.
Is “fool me once, shame on you; fool me twice, shame on me” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.