One of the principle pillars of any drug rehab program is education. The education component is crucial to maintaining a clean, drug abuse free lifestyle by providing the necessary life skills to avoid slipping back into addiction. Once an individual overcomes their addiction in a treatment facility they will have to return to the wider world. When the recovering addict does this, they will require tools to constructively overcome the hurdles they encounter along the way.
There is ample evidence to suggest that the earlier an individual is taught these crucial life skills, the less likely they will be to fall into drug abuse. The sooner these skills are imparted the better. But it is never too late to learn these best practices, or to simply reinforce them as a bulwark against unforeseen future challenges, whether drug related or not.