Alright, I will add a bit more context:

Academics are familiar with a related example: finishing our papers almost always takes us longer than we expected. We all know this and often say so. Why then do we continue to make the same error? Here again, the outside view does not inform judgments of particular cases.

From Timid Choices and Bold Forecasts A Cognitive Perspective on Risk Taking by Daniel Kahneman and Dan Lovallo