If you want to tell yourself that, ok. But don't pretend it's an actual fact.
>"Cognitive impairment by continuing or overuse of cannabis creates a form of mild dementia that may persist for up to several weeks after discontinuing the drug. Individuals sensitive to the drug report a persistent ì hangoverî that diminishes the ability to pay attention and concentrate. The onset may be insidious, subtle, and gradual.
"Paranoia and delusional thinking are not uncommon effects of cannabis both acute and chronically. In chronic use paranoid and delusional thinking appear to be the consequences of the suppression of feelings, the dulling of feelings may alienate the cannabis users from others by diminishing empathetic capabilities."
http://www.rxcbc.org/exd.html
see also: http://etd.vcu.edu/theses/available/etd-05032004-154113/
" Medical opinion, however, holds that marijuana contains 360 compounds besides cannabinoids, and the smoke of a marijuana cigarette contains noxious vapors of carbon monoxide, acetaldehyde and vinyl chloride, as well as phenol, creosol and naphthalene. Marijuana smoke also has twice as many cancer-producing substances (benzanthracene and benzopyrene) as tobacco cigarettes. Prolonged smoking of marijuana can result in persistent impairment of memory and of psychomotor performance, as well as emphysema-like symptoms."
http://www.aegis.com/pubs/bala/1994/BA940313.html
"Chronic health effects of cannabis use
*selective impairment of cognitive functioning which include the organization and integration of complex information involving various mechanisms of attention and memory processes;
*prolonged use may lead to greater impairment, which may not recover with cessation of use, and which could affect daily life functions;
*development of a cannabis dependence syndrome characterized by a loss of control over cannabis use is likely in chronic users;
*cannabis use can exacerbate schizophrenia in affected individuals;
http://www.who.int/substance_abuse/facts/cannabis/en/