You are incorrect. I had to do a huge report in debate class on why pot should be legal. I wasn't given a choice in the subject the teacher assigned it to me. If you don't believe me here is some reading material I suggest you look at.
Dr. Christine Hartel, Acting Director of Research, National Institute of Drug Abuse, cited by the State of Hawaii Dept of Health, Alcohol and Drug Abuse Division in memo of Feb. 4, 1994.
William Slikker et al., Chronic Marijuana Smoke Exposure in the Rhesus Monkey, Fundamental and Applied Toxicology 17: 321-32 (1991).
Charles Rebert & Gordon Pryor - Chronic Inhalation of Marijuana Smoke and Brain Electrophysiology of Rhesus Monkeys, International Journal of Psychophysiology V 14, p.144, 1993.
Cannabis and Memory Loss, (editorial) British Journal of Addiction 86: 249-52 (1991)