A word to the wise is enough

Proverbial Meaning: A wise person will take warnings into consideration, and act accordingly.

Literal Origins: A wise person need only be told that something is dangerous, where a stupid person will ignore others’ experiences and warnings, often hurting himself or herself.

Common Usage: A fairly well-known proverb. It is not commonly used in speech, but when it is used it will usually be quoted in full as a deriding comment to those foolish enough to ignore advice when they have fallen foul of their actions.