Learning by doing, and Failing. Do not underestimate any Story... it may cost you a lot!
Ericsson team members struggling with an apparently very simple problem... Everyone learns this by doing... or not? That's the point, often we make mistake and we believe that we learned not to do those mistake anymore... than one day, oh no... again! Why does this happen? Should an adult have learned to consolidate experience and make sure it becomes an asset? Well sure, most of us do, but than where is the problem?
A Team is not an individual, but many! And to consolidate the experience of the individuals into the Team, requires a bit more of work, than just what our brain - nearly naturally - provide us. We need to make sure that what every individual, or member, of the Team learns, becomes as fast as possible an asset, for the whole Team. This is the core of the "Build Knowledge/Amplify Learning" principle, it is up to every Team to define best practices to make sure that good results will be repeated
Sometimes also a "looking simple" task, under stress and pressure, may become a nightmare, a never ending story... does the Team know how to deal with this? Is the Team aware of the fact that a member is struggling without coming to an end? Is that member aware that sometimes it is needed to raise the hand and ask, and that doesn't mean "being not good enough" but means "being responsible"! Apparently not always We fear to understand that individual proud, ego and satisfaction are second to a common goal, and are spendable in favor of serving the Team... this is what an Agile Leader does!
So taking 4 Sprint to fix the roof of a LEGO house, may look really unrealistic, but it may still happen, important is that the Team learn as a Team and sets the adequate best practices to establish that learned lesson into the Team culture and assets.