Dan Gilbert 2: Why we make bad decisions

TEDGlobal 2005
Dan Gilbert: Why we make bad decisions  (script)
Daniel Gilbert is an American social psychologist and writer. This is his second TED talk.
His book "Stumbling on Happiness" is famous book. Somehow, Japanese title becomes "scientifically study Happiness of tomorrow."  I read this in the past in Japanese language. I like his point of views, because those are severe ideas that I didn't think and notice, but it'll be true. It gives me new perspectives.  I'm happy, because I can read this in English this time.
In this speech, the end Q&A is really interesting!
Chris Anderson is the owner of TED. He often questions to speaker to enjoy  with everyone on TED talk.
Jay Walker, one of America’s best-known business inventors. He has participated in TED talk two times, however, those are in 2008 (My library of human imagination) and 2009 (The world’s English mania) as far as I know. 
Aubrey de Grey is an English author and biomedical. He participants in this 2005.  His talk title is "A roadmap to end aging" that I was not convinced.
Summary
In fact, what tell us the right thing  at all possible time is the expected value and the odds that is probability.  The expected value of our actions is the hope that we can get.  What is produced by the odds is the action that will allow us to gain something and the value of that gain to us.
However, when we try making decisions, we make two mistakes.  Those  are 1) errors in estimating the odds that we're going to succeed, and 2) errors in estimating the value of our own success.
1) It's because we don't use the number of the right odds. We use some ideas that comes us faster. It means that we use what happens easily or we know something well or what is often announced. And then, we think that the news that don't come quickly to our mind doesn't happen. We vastly underestimate them. 
2) We also err calculating value, because we compare many things many times. When we decide how much we'll like something or we consume  something, we compare those values.  However, they are not the same comparisons. This is the problem of shifting comparisons. It makes us confuse though we want to make rational decisions.
If we can estimate the expected value and the odds, just only that time is that they are right.  Namely, they will change quickly. We will change our  minds when time pass, because we underestimated the odds of our future pains and overestimated the value of our present pleasures. 
Words in this story
stumbling / trip or momentarily lose one's balance; almost fall.
rational / logical
precise /  exact, accurate, correct, specific