Answer:
Robert's behavior is an example of maturing out.
Explanation:
This term is used for the process an addict has in which he/she has a recovery which can be natural or spontaneous, simply by the course of life. The individual stops struggling with the abuse of any substance he/she was addicted to.
In this case, Robert smokes less marijuana and stopped drinking, all because of life's course and his transition from college to the professional world.
