知ったこっちゃねぇんだよ！

[Crimson Firefly]

I've been reading a lot of shounen manga recently and I keep seeing "知ったこっちゃねぇんだよ！" (shitta koccha nee n da yo" and I'm not all to sure what it means. I tried to convert it to non-slang Japanese to try to understand it better and got: 知ったのはこっちじゃないのよ (shitta no ha kocchi ja nai no yo), but I'm not sure if this is right, because from the context I keep seeing it in it seems to mean something along the lines of "why should I care?".

Anyone care to shed some light on it?

[Ruby_MoonT]

I'm not 100% confident in this, but I'm pretty sure (about 95%). basically it's a slur from the original sentence.

知ったこっちゃねぇ -> 知ったこっちゃない -> 知ったことじゃない

if it is used in a sentence like 「俺の知ったこっちゃねぇんだよ!｣, basically means "it's none of my concern" while literally meaning "I don't know anything about it/regarding the matter"

[Cloudyboi]

its basically saying "i didnt know" in a very informal way.

the 'koccha' is actually an accent slur of koto+wa. its a way we add emphasis.

another variation of that slur is 'kotaa' (less often used)

but even without the 'wa' and it just being 'koto' it would mean the exact same thing.. only the emphasis rises when using 'koccha'.

hence, giving a fairly off-track translation such as "why should i care"
where as none* of those words even appear in the original sentence.

as for exact context, much like most of Japanese translated into English.. the equivalents* are many and they vary quite often.