If you hadn't reminded me of this matter, I would certainly have forgotten it.

亏了你提醒我，不然真把这事忘了。

《新英汉大辞典》

If you had the chance to spend the festival in China, I believe it would be a never-to-be-forgotten memory in your mind!

若你今年在中国过春节，我相信这一定会成为你最难忘的一件事的！

youdao

Dear Mr. Wang, I am much grateful to you provided a work opportunity for me during the past two months. This work experience I have never forgotten, it would be a precious wealth of my life.

Yours truly, Li Ming亲爱的王先生非常感谢您在过去两月里为我提供了一个工作机会，这段工作经历我将永生难忘，它将成为我人生中的宝贵财富。

youdao