Nearly 50% of people have tried an illegal drug at least once, yet most don’t repeat the experience. With cocaine, most who have tried it not only don’t go on to became addicts under even the most expansive possible definition of the term, they don’t even go on to become regular users.

According to the latest National Survey on Drug Use and Health, 14.5% of Americans ages 12 and older have tried cocaine at least once, but just 1.8% report using the drug recreationally in the past year. And just 0.6% have used it in the past 30 days, which would seem to be the minimal definition of a casual user.

The same pattern is true for heroin, which is typically talked about as magically addictive. Fear of the drug is surely one of the reasons why just 1.8% of Americans have ever tried it at all. But only 0.3% report using it in the past year and just 0.1% in the past month. That pattern simply shouldn’t be possible if these drugs were as addictive as commonly thought.

In the early 1970s, researcher Lee N. Robins led a study commissioned by the Department of Defense that followed tens of thousands of Vietnam War veterans as they returned to the U.S. Use of narcotics and heroin was rampant among soldiers stationed in Southeast Asia, with as many 20% showing signs of addiction. Yet during the first year back, “only 5% of those who had been addicted in Vietnam were addicted in the U.S.” and “at three years, only 12% of those addicted in Vietnam had been addicted at any time in the three years since return, and for those readdicted, the addiction had usually been very brief.” It wasn’t for lack of access to junk, either: half of the returning addicts said they’d tried heroin at least once since arriving back home.