“真想不到，你这么年轻，倒挺有主见”口语怎么说？

星星四语

口语翻译：
　　Upon my word, you give your opinion very decidedly for so young a person.
　　真想不到，你这么年轻，倒挺有主见啊!
　　【知识点讲解】
　　decidedly adv. 断然地;果断地;明确地;毫无疑问
　　例句：
　　He spoke so decidedly that I dared not question him.
　　他讲得那么坚决，我不敢质问他。