Yes, we did. So then, how is it that we don't learn from our mistakes? If we are well aware of the futility of prohibition, why do we continue to believe in it?
Of alcohol. That doesn't mean other things can't be prohibited.
If you don't think the prohibition of drugs is working, if you believe it's futile, then you must believe that if we ended it drug use would not increase.
Do you truly believe that?