不把……当回事

He thought nothing of people's advice, but now he is regretful.

他不把别人的意见当回事，但是现在他后悔了。

I think nothing of failure.

我不把失败当回事。

A：Thank you for giving me a hand.

谢谢你帮助我。

B：Think nothing of it, it's my pleasure.

别客气，这是我的荣幸。