Well that's what Columbia University professor Carl Hart learned in school too.
So imagine his surprise when his own research into drug addiction revealed something very, very different.
Working with others, Hart revisited some long-standing research on lab rats that showed that rats would self-administer drugs until death. He learned that rats that live in sterile cages with nothing else to do chose to take drugs until they effectively committed suicide. But those offered alternatives to drugs — like sweets or some hanky-panky — often chose the alternatives. In other words, the addictive behavior was caused by the environment, not some attribute of the drug itself.
Then Hart did something unusual. He invited human drug users into his lab. He set up an experiment where he offered regular meth users a choice between drugs or money.
When presented with an attractive alternative ($20), even people who regularly use a drug like meth still chose the alternative.