The time to make up your mind about people... is never.
8 seconds sound clip from the The Philadelphia Story movie soundboard.
You can hear this line at 01:13:08 in the Blu-ray version of the movie.
Quote context
[...]
- Well, maybe so, but all the same now, you can't do it.
- No?
- No.
- Come around about noon tomorrow. I mean today.
- Snob.
- Say, what do you mean, 'snob'?
- You're the worst kind there is - an intellectual snob.
- You've made up your mind awfully young, it seems to me.
- Well, 30's about time to make up your mind.
- And I'm nothing of the sort, not Mr. Connor.
- The time to make up your mind about people... is never.
- Yes, you are, and a complete one.
- You're quite a girl, aren't you?
- Thank you, Professor. I don't think I'm exceptional.
- I know any number like me. You ought to get around more.
- What, in the upper class? No, no. No, thank you.
- You're just a mass of prejudices, aren't you?
[...]