“"Nasruddin, four years ago you were here, and I asked that time also what is your age, and you told me forty years. Now this is absolutely inconsistent – how can you still be forty?"
Nasruddin said, "I am a man of consistency. Once forty, I remain forty always. When I have answered once, I have answered forever! You cannot lead me astray. I am forty, and whenever you ask you will get the same answer."”

Source: Autobiography of Mark Twain, Vol. 2 (2013), p. 115

Source: Dead in the Family

The Intelligent Woman's Guide To Socialism, Capitalism, Sovietism, and Fascism (1928)
1920s
Context: It is far more likely that by the time nationalization has become the rule, and private enterprise the exception, Socialism (which is really rather a bad name for the business) will be spoken of, if at all, as a crazy religion held by a fanatical sect in that darkest of dark ages, the nineteenth century. Already, indeed, I am told that Socialism has had its day, and that the sooner we stop talking nonsense about it and set to work, like the practical people we are, to nationalize the coal mines and complete a national electrification scheme, the better. And I, who said forty years ago that we should have had Socialism already but for the Socialists, am quite willing to drop the name if dropping it will help me to get the thing. What I meant by my jibe at the Socialists of the eighteen-eighties was that nothing is ever done, and much is prevented, by people who do not realize that they cannot do everything at once.

Circa 1970, '71 or '72, responding to the novel approach facetiously suggested by teammate Steve Blass, were he ever to be traded from the Pirates; as quoted in "A Teammate Remembers Roberto Clemente” by Steve Blass, as told to Phil Musick, in Sport (April 1973); reproduced in Clemente! https://books.google.com/books?id=n-4qAwAAQBAJ&pg=PT60 (1973) by Kal Wagenheim, p. 158
Baseball-related, <big><big>1970s</big></big>

The Gods of Pegāna, The Deeds of Mung (Lord of all Deaths between Peg&#257;na and the Rim)

In the title story Postcards from Surfers.
Garner describing her mother.
Postcards from Surfers (1985)

As quoted in Writers on Writing‎ (1986) by Jon Winokur.
Variant: If you ask me what I came into this life to do, I will tell you: I came to live out loud.

Marmee March to Jo, in Ch. 8 : Jo Meets Apollyon
Little Women (1868)
Context: You think your temper is the worst in the world, but mine used to be just like it. … I've been trying to cure it for forty years, and have only succeeded in controlling it. I am angry nearly every day of my life, but I have learned not to show it; and I still try to hope not to feel it, though it may take me another forty years to do it. … I've learned to check the hasty words that rise to my lips, and when I feel that they mean to break out against my will, I just go away for a minute, and give myself a little shake for being so weak and wicked.

Source: City of Heavenly Fire