salutary

a helpful or beneficial effect, often resulting from something unpleasant

有益な経験

an experience that is unpleasant but teaches a valuable lesson

不快ではあるが貴重な教訓を教えてくれる経験

a useful reminder of potential danger or problems

有益な教訓

a useful lesson learned from a bad experience

悪い経験から学んだ有益な教訓

有益な警告

a useful warning that helps to avoid a bad situation

不快ではあるが良い効果をもたらす警告