Because I might know you a little better than you think.

5 seconds sound clip from the The Notebook (2004) movie soundboard.

You can hear this line at 01:31:21 in the Blu-ray version of the movie.

Quote context

[...]

- You came down here. You knew what you were doing. You knew this would happen.

- Oh, so now I'm a tramp?

- You are unbelievable. Unbelievable.

- Go on and get some clothes on. Let's take a drive.

- Let's take a drive? Why would I want to go anywhere with you?

- Because I might know you a little better than you think.

- And I don't want you waking up one morning thinking that if you'd known everything, you might have done something different.

- What are we doing here, Mama?

- Do you see that man, there?

- Don't look like it now, but 25 years ago... oh my goodness, he was really something. We were out of our minds in love, let me tell you.

[...]