Understanding 自分は in this sentence (and other potential gross misunderstandings)


> 受話器を置き、口ひげをなでながら、ダーズリー氏は考えた。  
>  He put the receiver down and, while stroking his moustache, Mr Dursely
> thought.  
>  ------ **まさか、自分はなんて愚かなんだ** 。  
>  _I'm being stupid_

I'm really stuck on the line in bold.

So I guess I can translate まさか as "really". I think it intensifies the rest of
the sentence. Is this right?

I think なんて in this case is "how..." so まさか、なんて愚かなんだ would be "Really! How
stupid I am!"

So, if what I've got so far isn't gibberish, I don't know how to fit in the
自分は part. Literally I suppose it would be "Really! As for myself, how stupid I
am!".

But, is 自分は really necessary? Why? How should I think about it?




Translating this まさか as "Really!" is not wrong, but may be a bit too weak. I
feel it's closer to "That can't be!", "Unbelievable!", "I never dreamed of
it!", etc. It's not an intensifier but an interjection-like expression on its
own. That is, it's not directly connected to the remaining part of the
sentence.

自分は is necessary in this case. This is because まさか works as a comment about
the surprising news he just heard. Without 自分は that explicitly switches the
topic, the last half of the sentence would mean "How stupid it/he/she is!",
referring to the news. Compare:

> まさか、なんて愚かなんだ!  
>  Unbelievable! How stupid! (←this refers to the news itself)
>
> まさか、自分はなんて愚かなんだ!  
>  Unbelievable! How stupid I am! (←he is disappointed at himself because he
> could not think of the possibility of what he heard)




Translating this まさか as "Really!" is not wrong, but may be a bit too weak. I
feel it's closer to "That can't be!", "Unbelievable!", "I never dreamed of
it!", etc. It's not an intensifier but an interjection-like expression on its
own. That is, it's not directly connected to the remaining part of the
sentence.

自分は is necessary in this case. This is because まさか works as a comment about
the surprising news he just heard. Without 自分は that explicitly switches the
topic, the last half of the sentence would mean "How stupid it/he/she is!",
referring to the news. Compare:

> まさか、なんて愚かなんだ!  
>  Unbelievable! How stupid! (←this refers to the news itself)
>
> まさか、自分はなんて愚かなんだ!  
>  Unbelievable! How stupid I am! (←he is disappointed at himself because he
> could not think of the possibility of what he heard)

