Vacation amnesia refers to this situation: when you come back to school or work from your vacation, you can’t remember what you did before the vacation. Things you can’t remember may include: what project you were working on, any paper needed to be finished, or even who was taking care of your business when you were on vacation.

“假期失憶癥”指的是這樣一種情況：你度完假回到學校或單位后發現已經完全不記得度假之前你在做的事情。你當時正在進行的項目、有需要完成的論文、甚至度假時誰接手了你的工作都有可能不記得了。

For example:

Andy suffered from a bad case of vacation amnesia when he went back to school and couldn’t remember what he had been learning before.

安迪得了嚴重的“假期失憶癥”，他回到學校后根本不記得之前都學過些什么。