有意栽花花不发，无心插柳柳成阴
yǒu​yì​zāi​huā​huā​bù​fā, wú​xīn​chā​liǔ​liǔ​chéng​yīn

unpredictability

有意栽花花不发，无心插柳柳成阴 (有意栽花花不發，無心插柳柳成陰) yǒu​yì​zāi​huā​huā​bù​fā, wú​xīn​chā​liǔ​liǔ​chéng​yīn
unpredictability
things do not always turn out as expected; well-laid plans may fail while success may occur where least expected

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