Interactions with a former High School teacher

I was in Starbucks when I see a former English teacher of mine, and i'm pretty sure she thinks she's never seen me before in her life. Or in a past life. 

Conversation: 

Me: Hi! I'm one of your former students.

Mrs: Yes! I remember! What's your name?

Me: Mallory.

Mrs: Oh, right! Mallory! Mallory Richie right?

Me: No, Mallory Gardner..

Mrs: Oh, Mallory Gardner! Yeah, I remember. Wow it's been a wile. 8 years!

Me: Uhm, actually, like four. haha. (I awkwardly laughed, yes.)

Mrs. Oh, that's right 6. Wow.

Me: Oh. Um..

Mrs: So, you're like 20 now? How's that?

Me: Actually i'm turning 19 in May. Pretty excited though!

Mrs: Oh, Well it was nice seeing you.

I feel like that will be my interactions with high school teachers. Always.