What does「〜も何も」mean in this context?

Question

I’ve been studying Japanese for a while now and came across the following dialogue:

A: 私のこと、知ってるんだ。(So you know about me then?)
B: 知ってるも何も、有名人じゃないか。

I'm not quite sure how to make sense of B's reply. I thought it would translate to something along the lines of "I don't really know anything but you're a celebrity, right?" because of the use of 何も which I know means "nothing." However, the translation provided for B was "Of course I do (know about you), you're a celebrity, right?", which really confused me.

Initially I thought that the 〜も何も was just a combination of the particle も and the word 何も but apparently that doesn't seem to be the case. So my question is, what kind of meaning does「〜も何も」give to「知ってる」and how exactly does it translate to being an affirmation of one's knowledge about something? Can「〜も何も」be used with other words and what meanings would it have in those cases?

Answer 1

Look here for example:

「～も何も」は1つの例を出して、他のものを類推させるときに使います。

例 挨拶も何も

A: 「帰る前にあの人にあいさつしなきゃ」

B: 「挨拶も何も、あの人もう帰っちゃったよ！」

⇒挨拶も、会うことも、話をすることもできない

病気になってしまい、勉強も何もない。

⇒勉強も、遊びも、何もできない

In general it is used to give an example out of many and let infer the rest by analogy. Basically, when there is no room for doubt. I suppose you understand Japanese well enough and don't need a translation of the above quotation, let me know otherwise.

So, in your case I think it is used to answer using 知ってる as an example, among other many possible others, because for whatever reason there is no margin for doubt that B knows (here because A seems to be someone famous for example).

Another good example is from the link provided also by @ericfromabeno:

知ってるも何も→疑問の余地なく分かっているという意味かなと思います。

A「あのさ、この店知ってる？」

B「‘‘知ってるも何も‘‘俺が昔バイトしてたところだよ。」

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In your case, you can see it like something along the line of "Of course I know. I know very well, or, As a matter of fact, I do more than simply knowing..." (notice this is not a translation, since you already have it, but rather trying to convey the how to interpret 知ってるも何も).

Answer 2

知ってるも何も carries the idea of "it's not even a question of knowing X" or "I know all about X!"

In English, this might be one situation where we use the phrase "Of course": "Of course I know X."

a quick search found this Q&A on a language blog

http://lang-8.com/1486973/journals/96618803197205736526647859648046157520

and I am sure you could find more if you look around.