But why ? There ' s no evidence suggesting that drug use effects your ability to be successful . In fact many of the most famous rock musicians wrote their music whilst off their face . Just look at David Bowie . Undoubtedly one of the greatest musicians of all time and used a shit lot of recreational drugs . Drug abuse obviously does limit success , however in the vast majority of drug abuse situations the person abusing was already not successful . Poverty , being born into less stable family environment , and just not being as well off as others severely limits your ability to be successful . And how far would you go ? Does the use of alcohol hurt your opinion of people ? It ' s certainly more harmful than say cannabis .