He repented his thoughtlessness.

他后悔自己的轻率。

I deeply regret my thoughtlessness.

我深为反省自己的轻率。

Often, a large group of people against her thoughtlessness.

往往会得罪一大帮的人，成为众矢之的。

What women mistake as thoughtlessness is often just diffidence.

女性误以为是考虑不周的事情往往只是缺乏自信。

Imprudence or thoughtlessness in money matters would be unpardonable in me.

我要是在银钱问题上粗心大意，那是不可原谅的。