表示某人非常成功，就像掌握了全世界一样。
例如：
Marc finished school at the top of his class and he was offered an excellent position with an accounting firm. Now he feels that he has the world by the tail. Everything has been working out for him lately, and it's no wonder that he's feeling so successful and happy.
马克以优异成绩完成了学业，然后得到了一家会计师事务所的优质职位邀请。他现在觉得一切都在自己的掌控之中。最近，每件事都顺着他的意愿进行着，难怪他会觉得很有成就感，很高兴呢。