I'm not really surprised...是什么意思？

I'm not really surprised...

我其实并不惊讶。

not

adv. 不，[用以表示否定、否认、拒绝、禁止等]不是，几乎不，未必，没有[用于否定后面的词或短语]；

例句
It became very clear that the incident was not just an aberration, it was not just a single incident.
事实已经很清楚，这件事不是偶发的，它并不是一起孤立的事件。

really

adv. 真，真正，实在，果真，实际上，事实上；

例句
It's not really suited to absolute beginners...
它并不真正适合从零开始的初学者。

surprised

adj. 惊奇的，惊讶的，觉得奇怪的，感觉意外的；

例句
She had been surprised at how amiable and polite he had seemed.
看到他如此和蔼可亲、彬彬有礼，她非常惊讶。