Here is a list of common things of incorrect things I hear people say:
– it is a gateway drug (btw this is ridiculous because there is no direct mechanism in the brain that would cause it to be a gateway drug,) it gives a different high than other drugs and so people would not do a different drug to get the same or better high , cocaine may be a gateway to meth but that is only because the highs they produce are similar.
– legalizing it will make everyone smoke all day and nothing will get done (this is FALSE because studies have shown that legalizing it wont increase use and this is indeed the case for the Dutch)
– one marijuana joint is the same for your lungs as a pack of cigarettes (this is misleading because cigarette smokers will smoke more cigarettes than the number of joints a marijuana user will smoke)
– it is addictive (it is not addictive, I have watched the show Intervention and none of them were addicted to marijuana, I have never heard of someone whos life was ruined by marijuana addiction, I have heard of people going in and out of rehab or living on the streets due to cocaine, alcohol, meth, heroin, and others , but I have never heard of a single marijuana addiction story ( i have heard of people missing marijuana but it has been shown that this is different than addiction).
– it kills brain cells (this is FALSE, this has never been scientifically proven)
– it makes people lazy (marijuana does not make people lazy, it makes people giggly or calm (depending on the setting and the person) or a feeling of floating but it does not leave you lazy once you sobered up)
-only losers smoke pot (not true at all)
– marijuana increases schizophrenia 40% (this has been shown to be not true)
– it may causes a bunch of miscellaneous problems in some people (this is exaggerated , nearly every single medicine will have rare negative side effects that sound bad )
I have yet to hear a good reason to ban marijuana.