“Talk about the reality, about the facts, when to talk about children being killed, children of who? where? how? you're talking about propaganda, about media campaign, about sometimes fake pictures on the internet, we cannot talk but ones of the facts. We can talk about the facts, I cannot talk about allegations.”

Rejoinder when told that he couldn't talk about physics, because "nobody [at this table] knows anything about it."
Part 5: "The World of One Physicist", "Alfred Nobel's Other Mistake", p. 310.
Quoted in Handbook of Economic Growth (2005) by Philippe Aghion and Steven N. Durlauf.
Surely You're Joking, Mr. Feynman! (1985)

Source: The Wise Man's Fear

Source: I Touch the Earth, the Earth Touches Me

From books
Source: Jean Vanier, Community And Growth, 1979

Variant: If there is anything more annoying in the world than having people talk about you, it is certainly having no one talk about you.
Source: The Picture of Dorian Gray

Ways of Paradox and Other Essays (1976), p. 174
1970s

Variant: and it ought to make us feel ashamed when we talk like we know what we're talking about when we talk about love.
Source: What We Talk About When We Talk About Love

1960s, Address to Cornell College (1962)