Five years should be long enough to see people make changes, for good or for bad, though we won't see all the costs/benefits in the intervening time. Five years

Five years should be long enough to see people make changes, for good or for bad, though we won't see all the costs/benefits in the intervening time. Five years gives them enough time to make substantial time/education/skill investments in themselves by going to college/trade school, having a child, or learning a new skill. Five years also gives people enough time to develop negative habits/lifestyles such as drug or video game addictions. What change do you think would take more than five years to see?