My old Spanish nurse told me that half the people in the world would be ruined at once if everyone told what they knew.
7 seconds sound clip from the Beat the Devil (1953) movie soundboard.
You can hear this line at 00:37:28 in the Blu-ray version of the movie.
Quote context
[...]
- Letting those revolting men order you about.
- Don't deny it. I've watched them. They treat you like a servant. They say hop it, and off you hop.
- I know what it is. They have a hold on you. Some black secret that could ruin you.
- Oh, it happens all the time.
- But... couldn't you have them done away with?
- Why, you must know plenty of people who could bump them off.
- Probably cost a good deal, but it would be worth it, certainly.
- Maybe.
[...]