"Happiness has arrived" 的英文表达可以是 "Happiness is here" 或者 "Happiness has arrived"。这个表达的来源可能是人们希望表达快乐已经到来或者已经存在的感受。

一些英文例句和中文翻译如下：

The party was a success and happiness arrived as soon as the guests arrived. (聚会很成功，来宾一到就带来了快乐。)
Happiness is here at last! (终于，快乐来了！)
The sun is shining and happiness has arrived. (太阳正在照耀，快乐已经到来。)