a memory like a sieve是什么意思呀？

memory like a sieve

容易忘事、健忘、记忆很差

I'm sorry I didn't remember your birthday, I've got a memory like a sieve. 哎呀！很抱歉我忘了你的生日，我记忆真不好。

You'd better remind him about the party，he's got a memory like a sieve ! 你最好提醒他关于聚会的事情，他很健忘的！

The intro 

(Listening Comprehension)

Hey, what's going on everybody ? It's Mr.Wong here. Today's phrase of the day is "memory like a sieve". The definition of "memory like a sieve" is to be exceptionally forgetful or absent-minded. So if somebody can't retain things for long in his or her memory and quickly forgets, he or she has a memory like a sieve. A sieve has lots of tiny holes in it to let liquids out while keeping the solids inside. Let's check it out !

没看懂？请自己查字典！

(这才是真正的学习过程)