It is not advisable just to sit there brooding about the unpleasant bygones.

老是坐在那里闷闷不乐地想着去那些不愉快事情并不好。

The room had the elegance of a bygone era.

这个房间有着旧时优雅。

I’m willing to let bygones be bygones.

我愿意捐弃前嫌。

His talk was evocative of the bygone days.

他谈话令人回昔时日。

Let bygones be bygones and let's forget about our disputes and be friends again.

"去事不必再提了,让我们忘掉去争论,和好如初吧。"

This is a ridiculous situation, avoiding each other like this. Why can’t we let bygones be bygones?

我们这样互相迴避未免太可笑了，为什么不能忘记以前不愉快呢？