Four years seems like a long time in many respects. In November 2013, the U.S. Congress gave the pharmaceutical industry four years to figure out how to put a unique identifier (serial number) on every one of the Rx units-of-sale in the United States. On the face of it, it does not sound so difficult and is a respectable amount of time.
Then you look at the details of the law, research what is possible, put together a budget, build a schedule, define the resource and personnel requirements, and so on. Now, it is almost impossible to imagine… except everyone has to do it.