The “5 whys” technique was formally developed by Sakichi Toyoda and was used by Toyota while they were refining the way they manufacture their cars.
It is actually quite simple: when you ask why something is happening, we often take the first answer and go with that. However, usually there is much more to find out than we get initially. Mr. Toyoda suggested that we need to be more persistent in our questioning: by diving into whatever issue we have and peeling off layers of easy answers, we can get to the real reason. Repeat asking “why” for 3 to 5 times should get you to the core, or at least a lot closer, of almost any issue.
As soon as we know that, we truly learn and have the chance to make adjustments and changes that actually make sense.