When asked, many people wish to get better at estimation by tracking actuals and then assuming that some form of reflection upon those actuals will lead to better estimation. I've long held a belief that it doesn't happen quite so simply in reality. There are many assumptions in that proposal that are just glossed over. Let's list a few (just for fun): Actuals are accurate and precise representations, time will be allotted to reflections and learning, people (teams of people) will all arrive at similar conclusions and learn from the reflection of estimate not equal to actual, future behavior will change significantly and quickly, among other assumptions. Well finally science has something to say about this. A study: " How unrealistic optimism is maintained in the face of reality " by Tali Sharot , Christoph W Korn & Raymond J Dolan published in Nature Neuroscience (2011) has some fMRI proof that these behaviors are hard to change. In the stud