> You can drink a bit too much with 18 during a year and nicely recover. With marijuana, you smoke a bit too much during a year and you are good for life.

That's contrary to my understanding. I think you're overestimating the damage of one and underestimating the damage of the other. If you've underlying conditions susceptible to drinking or to smoking, indulgence in either can have dire consequences. For what it's worth, smoking for days straight is much much better in all ways than drinking for days straight.