“All young people worry about things, it's a natural and inevitable part of growing up, and at the age of sixteen my greatest anxiety in life was that I'd never again achieve anything as good, or pure, or noble, or true, as my O-level results.”

Interview at the 1989 Australian Grand Prix, November 1989 http://www.youtube.com/watch?v=n6brLntJE8s

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Your Job-Hunt Ltd – Advice from an Award-Winning Asian Headhunter (2003), Successful Recruitment in a Week (2012) https://books.google.ae/books?idp24GkAsgjGEC&printsecfrontcover&dqnigel+cumberland&hlen&saX&ved0ahUKEwjF75Xw0IHNAhULLcAKHazACBMQ6AEIGjAA#vonepage&qnigel%20cumberland&ffalse, Managing Teams in a Week (2013) https://books.google.ae/books?idqZjO9_ov74EC&printsecfrontcover&dqnigel+cumberland&hlen&saX&ved0ahUKEwjF75Xw0IHNAhULLcAKHazACBMQ6AEIIDAB#vonepage&qnigel%20cumberland&ffalse, Secrets of Success at Work – 50 techniques to excel (2014) https://books.google.ae/books?id4S7vAgAAQBAJ&printsecfrontcover&dqnigel+cumberland&hlen&saX&ved0ahUKEwjF75Xw0IHNAhULLcAKHazACBMQ6AEIJjAC#vonepage&qnigel%20cumberland&ffalse
Context: So many people give up too easily and as a result they never achieve the level of work success that might otherwise have been possible. People might overcome any hesitation in trying out something once, but in the face of the first setback, rejection or failure the majority of people would not continue and would simply give up. It is impossible to excel in your job and career if you are part of this majority - you would be leaving the minority who would be persevering, trying again and in many cases eventually succeeding. Can you imagine how many other light bulb inventors tried, failed and gave up during the time that Thomas Edison was showing amazing resilience by trying again and again until he eventually succeeded. Not giving up in itself is a form of excelling and would enable you to stand out amongst your colleagues.

Source: Where There's a Will: Thoughts on the Good Life (2003), Ch. 14 : Living with Children

On his years of research in developing the electric light bulb, as quoted in "Talks with Edison" by George Parsons Lathrop in Harper's magazine, Vol. 80 (February 1890), p. 425.
Context: During all those years of experimentation and research, I never once made a discovery. All my work was deductive, and the results I achieved were those of invention, pure and simple. I would construct a theory and work on its lines until I found it was untenable. Then it would be discarded at once and another theory evolved. This was the only possible way for me to work out the problem. … I speak without exaggeration when I say that I have constructed 3,000 different theories in connection with the electric light, each one of them reasonable and apparently likely to be true. Yet only in two cases did my experiments prove the truth of my theory. My chief difficulty was in constructing the carbon filament.... Every quarter of the globe was ransacked by my agents, and all sorts of the queerest materials used, until finally the shred of bamboo, now utilized by us, was settled upon.

Tallulah: My Autobiography (1952)

Source: Cuba’s Conscience https://www.catholicworldreport.com/2012/03/12/cubas-conscience/ (December 2011)

As quoted in "In conversation with Kate Bush" by Elio Iannacci in MacLeans (28 November 2016)
Context: The great thing about art on any level is that it can speak to all people if it’s achieved properly. When I’ve heard a piece of music or seen a painting that moves me, it gives me something. That’s such an incredibly special experience. I have intentions as a writer, but people — when they’re listening to a track — will take from it what they interpret. Sometimes people mishear my lyrics and think a song’s about something it isn’t. That doesn’t matter. If it speaks to them and they get something positive from it, it’s great.