But there are times when 60 Minutes has put that adage to the test. Sometimes, it's been to fairly important and intimidating people, like the Ayatollah Khomeini, as he held 52 Americans hostage at the U.S. Embassy in Iran.
"Imam, President Sadat of Egypt, a devoutly religious man, a Muslim, says that what you are doing now is, 'A disgrace to Islam,' says Mike Wallace. "And he calls you, Imam, forgive me, his words, not mine, 'a lunatic.' I know that you have heard that comment."
That question staggered the interpreter, who was afraid to translate it, and never did.
The legendary Admiral Hyman Rickover was as welcoming of critical questions as any ayatollah, as Diane Sawyer, then a 60 Minutes correspondent, found out.
"I never thought I was smart. I thought the people I dealt with were as dumb. Were dumb. Including you," says Admiral Rickover.
But it's not just admirals who can be offended by a question. Hollywood royalty expects only polite inquiries, too.
Cross over the line with Clint Eastwood, and without a word, he'll let you know with "The Look."
Steve Kroft: You've got lots of kids.
Clint Eastwood: Yeah. I have -- I like kids a lot.
Steve Kroft: How many do you have?
Clint Eastwood: I have a few.
Steve Kroft: Seven kids with five women, right? Not all of whom you were married to.
Clint Eastwood: No.
Steve Kroft: You would agree that this was somewhat unconventional?
Clint Eastwood: Yes. It's unconventional, yeah.
Steve Kroft: When I asked the question about the family, I have to tell you, that is a pretty awesome expression you have right now.
Clint Eastwood: Wha...
And then the look…
"I don't think I've had anybody look at me like that before," says Kroft. "It's a real Clint Eastwood look. It's intimidating."
Sometimes an interview can be even more uncomfortable than that. When Lesley Stahl met with H. Ross Perot, he had charged that his independent presidential bid had been sabotaged by a Republican dirty-tricks campaign.
"You have been in hot pursuit of this story and I have agreed to see you," says Perot, who accused Stahl of misrepresenting him.
When Stahl tried to set things straight, Perot stopped the interview.
Ross Perot: Let's stop the interview for a minute, we'll talk."
Lesley Stahl: No, I want to settle this. Please sit down.
Ross Perot: It's settled. You're not telling the truth, Lesley.
And there was Sen. Dennis DiConcini. The Senator refused to be interviewed about the very, very generous pensions Congress awards itself. So Lesley Stahl chased him down at the Lincoln Memorial, where she was about as welcome as Mike Wallace had been in Tehran.
Stahl: I'm wondering if you think it's fair that you, when you retire from Congress, are going to be getting a $55,000 pension right off the bat?
DiConcini: Well, Lesley, you're once again trying to destroy and run down Congress, and you shouldn't do that. You're a grown woman. You ought to have something better to do. Thanks a lot.
Stahl: As the Senator tried to beat a retreat, I followed along.
DiConcini: Now you've got your right to tear down anybody you want to do and you're doing a damn good job of it. I'm just sick and tired of it. Good night. Nothing personal.
But it's not just senators who don't like to be asked about money, as Mike Wallace discovered over and over and over again.
"Now who said I got three or four million dollars annually," asks Johnny Carson. "Nobody's ever quoted my salary correct and that's always intrigued me. Nobody's ever had the figure right."
Wallace asked Panama's then-dictator Manuel Noriega the same question. He received nothing but silence at first, and then, "BREAK, BREAK, BREAK, BREAK."
With Nancy Reagan, Wallace asked about her $2 billion, two-week tour in Japan.
"They're getting two of us. They're working us like crazy," says Reagan.
Would it be a well recompensed two-weeks? "It is for everybody who goes there, which you probably know," says Reagan. "Now you really didn't need that question."
There's another line of questioning that makes people as uncomfortable as asking about their money: Sex.
Take Ed Bradley and the Queen of Soul, Aretha Franklin. Bradley asked Franklin if he could talk to her about sex, on nationwide TV, in the family hour.
"I mean, it's, it's in a lot of your songs," says Bradley. "Lust. A feeling – good feeling."
"Got me mixed up with somebody else, Ed," says Franklin.
And when you ask about both money and sex in the same interview, it's enough to make even the unflappable Jerry Seinfeld, at the height of his TV popularity, sweat.
At the time, Seinfeld was involved with a UCLA student nearly half his age: "I think maybe it's because I'm so immature and she's so mature that we, we meet in the middle."
Steve Kroft: You think you're immature?
Jerry Seinfeld: Oh, yeah.
Steve Kroft: In what ways?
Jerry Seinfeld: Name one. Go ahead, name one.
Steve Kroft: Sexually?
Jerry Seinfeld: Yeah.
Steve Kroft: Why?
Jerry Seinfeld: I'm embarrassed.
Steve Kroft: Huh?
Jerry Seinfeld: I am not going to talk about being sexually immature on 60 Minutes .
Steve Kroft: But you think you are.
Jerry Seinfeld: It's not '60 Swinging Minutes,' you know?"
But if you think questions about sex and money can be a source of discomfort, try questions about race.
Ed Bradley did with one of the most successful writers working today, Nobel Prize winner Toni Morrison.
"I feel that white people will betray me. That in the final analysis, they'll give me up. If the trucks pass and they have to make a choice, they'll put me on that truck. That's really what I feel," says Morrison.
"By the way, there are lots of black people who'd put me on that truck also, so I'm not trying to demonize the white race. It's just a kind of a constant vigilance and awareness that maybe these relationships can go just so far."
The question of race also couldn't be avoided when Harry Reasoner profiled the quirky Jazz genius Miles Davis.
Harry Reasoner: Are you anti-white?
Miles Davis: Not all the time.
Harry Reasoner: That's encouraging. Not right now for instance, I hope."
Ed Bradley also talked to Lena Horne about her second husband, Lennie Hayton, a musical arranger who was also white and Jewish. For three years, Horne kept her marriage a secret.
"He had more entree than the black men," says Horne. But did she love him?
"Not at first. I learned to. He loved me very much, and I learned to love him because of how good he was to me, and patient and the things he taught me," says Horne.
"And he could come in the club with me and ask for this and that and the other and that would happen, where a colored man - I revert to that word, because in those days that's what we said - couldn't get me a job. And I had to love him for that, because you see, then I began to be very hungry for him to see me as black."
Even Andy Rooney has ventured into sensitive areas.
"We've all heard a lot about Camp David, the Presidential Retreat in Maryland, but we don't know what it looks like," says Rooney.
He decided to see how close he could get to Camp David. He turned in off the main road and kept gong a few hundred yards to the guardhouse at the gate. He received a very cool reception from some of the company of Marines guarding the place.
Then he asked if could get permission to take pictures. He was denied permission and was asked to turn off his camera.
"The Marines frisked our car, had us fill out intruder forms and asked Bob Peterson, the cameraman, to turn over the tape in his camera," says Rooney.
"We have those pictures you saw because by mistake Bob gave them a blank tape."