W: How can you forget to write your name again? Why can't you remember even though I have told you many times?

M: I'll remember it, but why should you be that harsh?

W: You just don't remember anything.

M: Sorry for losing one of your files and the computer.

W: What? How careless you are!

M: I already apologized for it.... Why should you be that harsh?

Everyone can make mistakes.

W: Why are you so unhappy?

M: I was just scolded by the manager.

W: Not a big deal. Everyone makes mistakes.

M: I'm likely to forget to sign my name and the position of the pay. I forgot again today.

W: It's okay. Everyone makes mistakes.

M: It is but a small fault. It will be terrible to make a big one.

Harsh: cruel, severe and unkind 残酷的;严酷的;严厉的
The punishment was harsh and unfair. 处罚很重而且不公平.
The minister received some harsh criticism. 部长受到了严厉的批评.
He regretted his harsh words. 他对自己的刻薄言辞感到后悔.
We had to face up to the harsh realities of life sooner or later. 我们迟早都得正视生活的严酷现实.

Scold: to speak angrily to somebody, especially a child, because they have done something wrong 训斥,责骂(孩子)
He scolded them for arriving late. 他嫌他们迟到,训了他们一通.

not a big deal: 不是什么大事;不要紧