As a kid, in love with light sabers and spaceships, I took Yoda's words to heart. It helped that he had a more-than-passing resemblance to the LDS leader at the time.

As an adult, I see the little muppet's words differently.

We love certainty in our prognosticators.

"I will love you forever"
"We will win this election"
"We cannot fail"
"I'm gonna kick his ass"
"Jesus will come again on December 5, 1896"

Something is lost when we are honest about our inability to predict the future.

"I love you now, and will probably love you for many more years"
"It is looking good that we can win this election"
"Failure would be very bad for us"
"I'm going to fight him and attempt to win"
"Jesus will be back someday"

Ask John Kerry how well the people understand a nuanced view of the future as probabilities. Ben Bernake is having the same problems. Everyone loved that Greenspan couched his predictions, Nostradamus-like, in convoluted edicts. Bernake speaks plainly by comparison: an academic, discussing probabilities.

But honest assessments of probability don't persuade and don't lead people to action. As I'm entering the world of competitive sports I am reminded why I didn't connect with them in the first place. Everyone talks of winning, pushing themselves harder than the next guy, wanting it more. But once we go from probability to actuality, there can be only one winner and that person will win based on many variables that are out of everyone's control (ask the Patriots how that goes down).

So what to do? No one wants to act on a probability of success. Even gamblers tell themselves that this time is the one when they'll win. See how far you get with that hot chick when you say "I'm not certain how I'll feel about you in the morning because right now I'm under the influence of a surge of hormones and those will disappear after we have sex and then I may hate you, I may not."

You probably won't get to find out.

In the end, you have to "do" but that's just a cover-up: you are really only just trying.