I'll try if I know all the things I used to know.

如果我知道所有我过去知道的事情，我会试一试。

youdao

I used to know your pa.

我过去跟你爸爸很熟。

《牛津词典》

She's a dead ringer for a girl I used to know.

她酷似我以前认识的一个女孩。

《牛津词典》

When I used to know you so well Yeah, yeah, yeah How did we get here?

VOA: standard.other

You remind me of a girl I used to know.

你让我想起了一个以前认识的女孩。

remind me of 实战 - SpeakingMax英语口语达人

I have no idea what's here at the moment so I'm just going to draw a question mark because that memory might have been used previously for some other purpose, but we know it's currently available to us so we have four bytes of memory.

我不知道在此刻这里是什么,所以我画一个问号，因为那块内存可能在之前,为其它的目的而使用过，但是我们知道它可以为我们所使用,这样我们就有4个字节的内存。

哈佛公开课 - 计算机科学课程节选

They include Adele's Someone Like You and Somebody That I Used To Know, by Gotye featuring Kimbra.

BBC: Elton John Diana tribute tops best-selling single chart

Gotye's Somebody That I Used To Know was the year's top-selling song after being downloaded 6.8 million times.

BBC: Adele tops US chart again in 2012

Gotye's Somebody That I Used To Know was the most-streamed song of 2012.

BBC: Digital music 'becomes mainstream' in the UK