This nation learned nothing from Prohibition. Nothing.
Just as people have learned nothing from their abuse of drugs.
Well, we learned how many people once favored & still do favor enlisting Big Government to control what adults put in their own bodies (yet still consider themselves "conservative").
And you have learned nothing about drug dependency.
We learned that Libertarians will constantly compare alcohol and narcotics while using the word "Prohibition" and assert they are exactly the same thing when in fact they are very very different.
Alcohol has been part of the culture as far back as human history records. It is engrained in the society and has always been so. These various narcotics, of which Marijuana happens to be one of the least dangerous, have not been widely used for any significant length of time.
They are not ingrained in the social fabric and nor should we allow them to become ingrained.
Alcohol kills about 85,000 people per year, and does untold other damage, but society has deliberately chosen to accept these losses. We should not be wanting another drug to add death and misery to the toll already exacted from the other one.
To the contrary, they learned a lot from prohibition. The governement got bigger, more powerful and corruption was widespread. That's all the government could want out of any policy.