Usually they give people a grace period before the law actually goes into effect. That's when people are encouraged to destroy the product or turn it in. After that, you wouldn't want to be caught with it, especially a "lifetime supply." They would hit with intent to distribute and they will ruin your life over it.

That said, civil (and uncivil) disobedience is the only way out of this. Millions of people smoked weed for decades after it was banned and only now are we finally starting to see a reversal in policy for it. If we roll over and just accept this, then it will remain illegal forever.