„If you don't understand yourself you don't understand anybody else.“

„I don't understand you. You don't understand me. What else do we have in common?“

—  Ashleigh Brilliant American author and cartoonist 1933

„If you can't explain it to a six year old, you don't understand it yourself.“

—  Albert Einstein German-born physicist and founder of the theory of relativity 1879 - 1955

Variante: If you can't explain it to a six year old, you don't understand it yourself.

„… you don't realize whether or not you completely understand a topic until you are tasked to explain it to someone else. … That really challenges your understanding of a topic.“

—  Steven Novella American neurologist, skepticist 1964

SGU, Podcast #170, October 22nd, 2008 http://www.theskepticsguide.org/podcast/sgu/170
The Skeptics' Guide to the Universe, Podcast, 2000s

„I don't always understand poetry!'

'You don't always understand it? Timms, I never understand it. But learn it now, know it now and you will understand it… whenever.“

—  Alan Bennett, The History Boys

Fonte: The History Boys

„If you think technology can solve your security problems, then you don't understand the problems and you don't understand the technology.“

—  Bruce Schneier American computer scientist 1963

preface to 2015 edition of Secrets and Lies
Cryptography
Contexto: A few years ago I heard a quotation, and I am going to modify it here: If you think technology can solve your security problems, then you don't understand the problems and you don't understand the technology.

„In general, I feel if you can't say it clearly you don't understand it yourself.“

—  John Rogers Searle American philosopher 1932

„Anything you don't understand is dangerous until you do understand it.“

—  Larry Niven, livro Flatlander

"Flatlander" (1967), first published in If (March 1967)

„I teach identity leadership, based on the philosophy that you can’t lead anybody else until you lead yourself. Once you understand who you are, you can really focus on becoming the expert in your field.“

—  Stedman Graham American businessman 1951

Financial Post: "'The key is to know who you are': Stedman Graham talks investing, self-leadership and Oprah" https://business.financialpost.com/executive/leadership/the-key-is-to-know-who-you-are-stedman-graham-talks-investing-self-leadership-and-oprah (27 April 2018)

„I can't relate to lazy people. We don't speak the same language. I don't understand you. I don't want to understand you.“

—  Kobe Bryant American basketball player 1978 - 2020

„I pretend to understand because I don't want anybody to be hurt“

—  Charles Bukowski, livro Hollywood

Fonte: Hollywood

„I don't understand it any more than you do, but one thing I've learned is that you don't have to understand things for them to be.“

—  Madeleine L'Engle, livro A Wrinkle in Time

Fonte: A Wrinkle in Time

„You really don't understand. We don't worry about individuals.“

—  A. E. van Vogt, livro The Weapon Shops of Isher

Lucy Rail, and Cayle Clark in Ch. 5
The Weapon Shops of Isher (1951)
Contexto: "You really don't understand. We don't worry about individuals. What counts is that many millions of people have the knowledge that they can go to a weapon shop if they want to protect themselves and their families. And, even more important, the forces that would normally try to enslave them are restrained by the conviction that it is dangerous to press people too far. And so a great balance has been struck between those who govern and those who are governed."
Cayle stared at her in bitter disappointment. "You mean that a person has to save himself? Even when you get a gun you have to nerve yourself to resist? Nobody is there to help you?"
It struck him with a pang that she must have told him this in order to show him why she couldn't help him.
Lucy spoke again. "I can see that what I've told you is a great disappointment to you. But that's the way it is. And I think you'll realize that's the way it has to be. When a people lose the courage to resist encroachment on their rights, then they can't be saved by an outside force. Our belief is that people always have the kind of government they want and that individuals must bear the risks of freedom, even to the extent of giving their lives."

„Don't criticize what you can't understand.“

—  Bob Dylan American singer-songwriter, musician, author, and artist 1941

„You never understand anybody that loves you.“

—  Ernest Hemingway, livro Islands in the Stream

Pt. 3: At Sea, Section 21 (the last sentence of the novel)
Islands in the Stream (1970)

„Now I understand. When you love someone, you have to try things even if they don't make sense to anyone else.“

—  Gennifer Choldenko, livro Al Capone Does My Shirts

Fonte: Al Capone Does My Shirts

„Will you understand what I'm going to tell you? … No, you're not going to be able to understand it. … That is because I don't understand it. Nobody does.“

—  Richard Feynman, livro QED: The Strange Theory of Light and Matter

Fonte: QED: The Strange Theory of Light and Matter (1985), p. 9

„If you don't understand other people in their time and why they did what they did, then you don't understand your own past. And when you lose your past, you lose some potential for your own future.“

—  C. J. Cherryh United States science fiction and fantasy author 1942

The Camelot Project interview (1996)
Contexto: When the legend is retold, it mirrors the reality of the time, and one can learn from studying how various authors have attempted to retell the story. I don't think we have an obligation to change it radically. I think that if we ever move too far from the basic story, we would lose something very precious. I don't, for instance, approve of fantasy that attempts to go back and rewrite the Middle Ages until it conforms to political correctness in the twentieth century. That removes all the benefit from reading the story. If you don't understand other people in their time and why they did what they did, then you don't understand your own past. And when you lose your past, you lose some potential for your own future.

„He wrote Helen that "a part of adolescence is feeling that there's no one else around you who's enough like yourself to understand you."“

—  John Irving, livro The World According to Garp

The World According to Garp (1978), ch. 5

„What you don't understand you can make mean anything.“

—  Chuck Palahniuk, livro Diary

Variante: What we don't understand we can make mean anything.
Fonte: Diary