What causes addiction?
Stupid people cause addiction. See my proof below.
In the early 20th Century, it was a proven fact that heroin was addictive.
But in the 1970's some smart people thought, maybe addiction is caused by the environment the subject is in. So they moved Ricky the Rat to Rat Wonderland, where he would have plenty of places to play, plenty of friends and even lady friends!
Later that day ...
The End.
This lazy comic was inspired by this video on addiction.