“Still, all this time, I was only barely aware that my subconscious was putting together a layout of the house. It wasn't that I expected to need one, it's just how my mind works. I am, quite frankly, very good at it, and maybe that's where the real pleasure comes in — just the joy of doing something you do well. There are worse reasons for doing things; maybe there aren't any better ones.”

Source: The Dud Avocado

As quoted by Amanda Gefter (from the symposium in honor of Wheeler's 90th birthday) [Trespassing on Einstein's lawn: a father, a daughter, the meaning of nothing, and the beginning of everything, 2014, https://books.google.com/books?id=NUMkAAAAQBAJ]

Interview in The Guardian, 25 January 2006 http://www.guardian.co.uk/media/2006/jan/25/broadcasting.bigbrother

Edward Everett Hale in a statement published in A Year of Beautiful Thoughts‎ (1902) by Jeanie Ashley Bates Greenough, p. 172; <!-- and perhaps as early as an edition of Ten Times One is Ten (1870) by Hale--> This has been misattributed to Keller in published works since at least 1980. Keller and Hale were good friends, and letters to Hale can be found in her youthful autobiography The Story of My Life (1902). In 1910 Keller dedicated her poem "The Song of the Stone Wall" to Hale who had died in 1909.
Misattributed
Variant: I am only one, but I am one. I can not do everything, but I can do something. I must not fail to do the something that I can do.

Statement published in A Year of Beautiful Thoughts‎ (1902) by Jeanie Ashley Bates Greenough, p. 172, Third statement for June 11. This has often been misattributed to Helen Keller in some published works since at least 1980, perhaps because she somewhere quoted it.
Variant:
I am only one,
But still I am one.
I cannot do everything,
But still I can do something;
And because I cannot do everything,
I will not refuse to do the something that I can do.
The Book of Good Cheer : A Little Bundle of Cheery Thoughts‎ (1909) by Edwin Osgood Grover, p. 28; also in Masterpieces of Religious Verse (1948) by James Dalton Morrison, p. 416, where it is titled "Lend a Hand"
Variant: I am only one, but still I am one. I cannot do everything, but still I can do something; and because I cannot do everything, I will not refuse to do something that I can do.

In an interview (March 1960) with David Sylvester, edited for broadcasting by the BBC first published in 'Location', Spring 1963; as quoted in Interviews with American Artists, by David Sylvester; Chatto & Windus, London 2001, p. 54
1960's

Catching Up with DS9’s Rene Auberjonois http://www.startrek.com/article/catching-up-with-ds9undefineds-rene-auberjonois-part-1 (June 7, 2011)