I have some close friends who started smoking at 18, and by 21 were pretty hooked, would rather not smoke, but found quitting too difficult. I have a feeling this will do a good job of reducing addiction rates.

At the same time I do feel like adults should be adults full-stop and think it’s ridiculous you can be drafted, vote and serve in military and not drink or smoke (or rent a car!). Maybe the age of adulthood should be moved to 21 altogether.