“To be a great champion you must believe you are the best. If you’re not, pretend you are.”
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Muhammad Ali 100
African American boxer, philanthropist and activist 1942–2016Related quotes

I'll never forget what Jeremy Corbyn whispered in my ear at a campaign event last week http://www.independent.co.uk/voices/jeremy-corbyn-labour-manifesto-policies-what-was-in-whispered-in-my-ear-campaign-rally-a7738776.html, article by Harriet Williamson, in The Independent (16 May 2017).
2000s

https://naijagists.com/omotola-jalade-ekeinde-wisdom-quotes-top-20-motivational-quotes-sayings-omosexy/ Omotola Jalade Ekehinde speaking on Success.

Quando non si è sinceri bisogna fingere, a forza di fingere si finisce per credere; questo è il principio di ogni fede.
Source: Gli indifferenti (1929; repr. Milano: Corbaccio, 1974) p. 238; Tami Calliope (trans.) The Time of Indifference (South Royalton, Vt.: Steerforth Press, 2000) p. 207.

This is Really Irene Dunne, by Sara Hamilton http://www.irenedunnesite.com/press/photoplay-april-1936/; Photoplay (April 1936).

Source: Your Best Life Now: 7 Steps to Living at Your Full Potential

“I always work on the theory that the audience will believe you best if you believe yourself.”
Los Angeles Times interview (1956)
Context: I always work on the theory that the audience will believe you best if you believe yourself. This meant that I had to come to understand Moses well enough to believe in my portrayal of him.

“I’m really willing to try to believe you’re not crazy, but you gotta help me a little, you know?”
Source: Last Call (1992), Chapter 37 (p. 374)

CM Punk/John Morrison contract signing http://youtube.com/watch?v=6EUO__hwKvE