- I'll bet I know something you don't know.
- What's that?

3 seconds sound clip from the Play It Again, Charlie Brown movie soundboard.

You can hear this line at 00:04:21.607 in the DVD version of the movie.

Quote context

[...]

- Did anyone ever tell you that you have pretty eyes, Schroeder?

- Musicians get unnerved when you tell them they have pretty eyes.

- Schroeder, do piano players make a lot of money?

- Money? Who cares about money? This is art. This is great music I'm playing. And playing great music is an art. Do you hear me? An art. Art, art, art!

- You fascinate me.

- I'll bet I know something you don't know.

- What's that?

- Beethoven now comes in a spray can.

- Schroeder, I think it's disgraceful the way Lucy bothers you.

- And she's always asking everyone: Why does he have to play that stupid piano? I think that's terrible. Incidentally, why do you always have to play this stupid piano?

- What are you doing here? Who wants to know? Maybe I just like music.

[...]