Grammar of Shinunoga E-wa lyric: "そんなダサいこと もうしたないのよ goodbye"


I am have trouble understanding this verse _そんなダサいこと もうしたないのよ goodbye_

The context is

> 失って初めて気がつくなんて  
>  そんなダサいこと もうしたないのよ goodbye

My translation:

Line 1: The is _bad_ -thing [なんて] it is the first time [初めて] I notice [気がつく] I
lost you [失って]

Line 2: Lame thing [ダサいこと] like this [そんな] I already did [もうした] ... ないのよ [will
not do]

I am having difficulty in understanding why ない comes after a verb in the past
tense [した]. Shouldn't it be grammatically [したなかった] ? Or is this new slang ?




[Full lyrics in Uta-Net](https://www.uta-net.com/song/285543/)

  * This したない is an informal and dialectal variant of したくない, "not to want to do". In some western dialects, the く of the ku-form of an i-adjective is commonly replaced to an elongated vowel (e.g., あかくない → あかあない, あつくて → あつうて, ひどくない → ひどおない, したくない → したあない). When this happens before ない in hasty speech, the long vowel is occasionally shortened (e.g, あかあない → あかない, ひどおない → ひどない, したあない → したない).
  * 失って初めて気がつく means "to lose (something) and (then) notice (something) for the first time", or more naturally, "to notice (something) only after losing (something)". In the song's context, the implicit object of 失う is あなた, and the implicit target of 気がつく is the value/importance of the lost thing (あなた).
  * もう is "(not) any more" rather than "already" here.

> 失って初めて気がつくなんて そんなダサいこと(は) もうした(く)ないのよ
>
> I no longer want to do such a lame thing like noticing the importance of
> something only after losing it.

Or a free translation is "Realizing how important you are only after losing
you, I no longer want to do something lame like that."

Although I don't think this is directly related to the lyrics in question,
this type of "く-omission" was popular for a while as nerdy internet slang.
See: [Omission of く in negative form of
い-adjective](https://japanese.stackexchange.com/q/46913/5010)




[Full lyrics in Uta-Net](https://www.uta-net.com/song/285543/)

  * This したない is an informal and dialectal variant of したくない, "not to want to do". In some western dialects, the く of the ku-form of an i-adjective is commonly replaced to an elongated vowel (e.g., あかくない → あかあない, あつくて → あつうて, ひどくない → ひどおない, したくない → したあない). When this happens before ない in hasty speech, the long vowel is occasionally shortened (e.g, あかあない → あかない, ひどおない → ひどない, したあない → したない).
  * 失って初めて気がつく means "to lose (something) and (then) notice (something) for the first time", or more naturally, "to notice (something) only after losing (something)". In the song's context, the implicit object of 失う is あなた, and the implicit target of 気がつく is the value/importance of the lost thing (あなた).
  * もう is "(not) any more" rather than "already" here.

> 失って初めて気がつくなんて そんなダサいこと(は) もうした(く)ないのよ
>
> I no longer want to do such a lame thing like noticing the importance of
> something only after losing it.

Or a free translation is "Realizing how important you are only after losing
you, I no longer want to do something lame like that."

Although I don't think this is directly related to the lyrics in question,
this type of "く-omission" was popular for a while as nerdy internet slang.
See: [Omission of く in negative form of
い-adjective](https://japanese.stackexchange.com/q/46913/5010)

