Once you've met someone, you never really forget them. It just takes a while for your memories to return.
9 seconds sound clip from the Spirited Away movie soundboard.
You can hear this line at 01:50:09 in the Blu-ray version of the movie.
Quote context
[...]
- You'll have to help your parents and Haku on your own.
- Use what you remember about them.
- What? Can't you please give me more of a hint than that?
- It seems like I met Haku before, but it was a long time ago.
- While you're thinking, the boys and I are going to make you something.
- And I want you to call me Granny from now on.
- No-Face, where did you learn to spin thread? You're really good at this.
[...]