No. That was a little girl named Mary Hatch. That wasn't you.
5 seconds sound clip from the It's a Wonderful Life (1946) movie soundboard.
You can hear this line at 00:21:09 in the Blu-ray version of the movie.
Quote context
[...]
- Why don't you stop annoying people?
- You look at me as if you didn't know me. Well, I don't.
- You've passed me on the street almost every day. Me?
- No. That was a little girl named Mary Hatch. That wasn't you.
- Oh, yes! Oh, yes! Oh, yes! The big Charleston contest!
- The prize, a genuine loving cup.
- Those not tapped by the judges will remain on the floor.
- I'm not very good at this. Neither am I. Okay. What can we lose?
[...]