"have the world by the tail" in Chinese (Simplified)
如鱼得水得意洋洋
Definition
处于非常成功和自信的位置，觉得一切都顺利，没有什么可以阻挡你。
Usage Notes (Chinese (Simplified))
这是非正式和积极的习语，形容某人处于顶峰或很成功。常用于重大成就之后。类似于“如鱼得水”。
Examples
After getting the new job, she had the world by the tail.
得到新工作后，她**如鱼得水**。
He felt like he had the world by the tail after winning the contest.
赢得比赛后，他觉得自己**得意洋洋**。
When I graduated from college, I thought I had the world by the tail.
大学毕业时，我以为自己**得意洋洋**。
With that big promotion, you really have the world by the tail now.
有了这次大提拔，你现在真的**得意洋洋**了。
Ever since he started his own company, he’s walked around like he has the world by the tail.
自从他创立了自己的公司，他总是一副**得意洋洋**的样子。
Don’t get cocky just because you have the world by the tail for now.
别因为现在**得意洋洋**就骄傲自满。