" The human mind has limits. We can only remember so many things; we can really only concentrate on one thing at a time. This tendency—for the process of fixing things to get harder as more time elapses—represents a similar limitation. When you’re working on a project, there’s a whole mind space that you create around it. You know all the different reasons why something is being done. You’re holding a pretty complicated construct in your head. Re-creating that construct a week later is hard. You have to remember all the factors that you were considering when you made that choice. You have to re-create the thought process that led you to that decision. You have to become your past self again, put yourself back inside a mind that no longer exists. Doing that takes time. A long time. Twenty-four times as long as it would take if you had fixed the problem when you first discovered it. "

― Jeff Sutherland , Scrum: The Art of Doing Twice the Work in Half the Time