有心栽花花不开，无心插柳柳成荫。

Planted with or abounding in willows.

我喜欢无心插柳柳成荫的那种偶然。

I like the unintentional positive outcomes of the kind occasionally.

一说“无心插柳柳成荫”。春天的杨柳，总给人旺盛生命力之感。古人“折柳赠别”蕴含着“生机昂然，落地生根”的祝愿。

One says "step". In the spring of willow, giving people a sense of vitality. The ancients "broken orange" imply "on parting in life with confidence, put down roots" wishes.

最好就是无心插柳柳成荫的这种多态，这种情况下你会发现某个之前写过的函数可以用来处理一个之前没有计划到的类型。

The best kind of polymorphism is the unintentional kind, where you discover that a function you already wrote can be applied to a type you never planned for.