I'm amazed at my exam results - I hadn't expected to do so well.

【翻译】我对自己的考试成绩感到惊讶 —— 我没想到考得这么好。

“过去完成时”， 除了表示“过去的过去” 用法之外，还用来表示过去“未曾实现的愿望或打算”。hope, wish, plan, want, mean, intend, attempt, think, expect 等表示“打算、计划、希望、试图、认为” 等的动词，用过去完成时表示过去未曾实现的愿望、打算或意图等。例如：

I had hoped to see her again.

我本希望再见她一面。

The boy had intended to buy his mother a birthday gift.

那个男孩本打算给他妈妈买一件生日礼物。

Monica had meant to have a birthday party but no one came.

莫尼卡本想举办生日聚会，但是没有人来。

They had planned to go on an outing yesterday,but it was raining.

他们本计划昨天去郊游，可是一直下雨。