Back-to-back contestants on "Who Wants to be a Millionaire" have just demonstrated the truth of the above premise. The first was a woman who said up-front that she and her husband had a slogan, "If it's not 100%, you gotta pay the rent", meaning they had decided she shouldn't guess if she wasn't 100% sure. I have demonstrated in a previous post here that this is a completely wrong approach. The right approach balances the potential risk vs. the potential reward, and if the reward is greater, then you go for it. The rubber hit the road with this contestant when she was going for $100K, had it down to 2 choices, and still walked instead of guessing. She would have been risking $25K to win $50K, an obvious spot to guess, but contestants just can't seem to understand this risk vs. reward concept.
To make me even more discouraged about the innumeracy of the populace, the very next contestant came in with a saying written on his hand; it was "don't guess". He showed he was following this ridiculous slogan by asking the audience on a $2K question, where the answer was obvious, and then on the $4K question, which gave a name (which I didn't right down), and said this name "which reads the same forwards and backwards, is a fear of what"? It obviously was palindrome, yet he called a friend, who put the word into his computer and still had no answer, then he used his 50-50, and then he walked!! Perhaps he didn't know what a palindrome was, but that seems rather far-fetched. I think he was just stupidly following his silly slogan.
Just consider, how many great achievements in history would never have happened if the people had the attitude of not trying unless 100% sure of success? Life is uncertain, it is a matter of taking risks, and if you are never willing to take a risk, you will never accomplish anything worthwhile.