“I know that if I am not at my best and I do not perform I will lose. I'm never over-confident. Over-confidence is a weakness because it stops you training as hard as you should. It has happened to fighters like Naseem Hamed and Lennox Lewis. Complacency beats fighters.”
Calzaghe before his fight against Mikkel Kessler of Denmark http://news2.thdo.bbc.co.uk/sport1/hi/boxing/7062510.stm.
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Joe Calzaghe 1
Welsh boxer 1972Related quotes
Source: The Anarchist Cookbook (1971), Chapter Three: "Natural, Nonlethal, and Lethal Weapons", p. 92.
Context: It is easy to pick up a weapon and in a short while become a reasonably good shot. This makes it extremely easy for the virtually untrained individual to come to believe that he is an expert in ballistics. False confidence is as great a fault as no confidence at all. In the training of any freedom fighters there must be a merger of fearlessness and intelligent caution. A dead man has no use for confidence or courage.

“I want to be the best fighter. I would like to fight in the biggest fights.”
Conference Call before the "Blaze of Glory: Pacquiao vs. Solis"
As quoted in "Manny Pacquaio/Bob Arum Conference Call Transcript," http://www.eastsideboxing.com/news.php?p=10519&more=1 at East Side Boxing (2007-07-04)

“I feel confident because I'm the best player in the world. It's that simple.”

“I am a fighter and not a quitter!”
Jason Beattie, Jon Hibbs, "Triumphant Mandelson hails new Labour victory", Scotsman, 8 June 2001, p. 5.
Acceptance speech after re-election as MP for Hartlepool in the 2001 General Election.
Context: Before this campaign started, it was said that I was facing political oblivion, my career in tatters, apparently never to be part of political life again. Well they underestimated Hartlepool and they underestimated me, because I am a fighter and not a quitter!My political opponents can have their pound of flesh, and they do, but they will not eat into of my beliefs, what I stand for and have done in politics. That is the inner steel in me.

https://www.youtube.com/watch?v=BF-sxSipAMs
https://thefamouscelebrity.com/mike-tyson-wiki/
On boxing

The Best of The Sunday Edition, CBC.ca, CBC, Michael Enright, October 25, 2009, November 5, 2009 http://podcast.cbc.ca/mp3/sundayedition_20091026_22073.mp3,