I hadn't heard much about fentanyl until it really started killing people.
You'd see discarded needles in some of the shadier parts of my old East Harlem neighbourhood, but the drug's real impact was outside of the big cities in the US North East.
In Maine, New Hampshire, and rural Massachusetts, hundreds of people began dying from heroin or heroin/fentanyl overdoses. The potent opiate, usually prescribed to cancer patients, was increasingly being mixed with other drugs.
Sometimes people knew what they were taking, sometimes they didn't.
In 2014, the Governor of Vermont, a state best known for its tranquillity and kindliness, dedicated every word of his annual State of the State speech to an epidemic of overdose deaths.
Fentanyl is here. Customs has seen it at the border, and although New Zealand Police are yet to make any seizures, it has already been linked to ten deaths in Melbourne.
It's a terrifyingly powerful drug, 50-100 times more potent than morphine. Tiny amounts can kill, and quickly. In May, a police officer in Ohio overdosed after brushing a bit of fentanyl powder from his uniform using his bare hand.
More New Zealand politicians are beginning to appreciate decades of the prohibit-and-prosecute model hasn't worked in curtailing drug use.
Increasingly, it is being considered a health issue rather than a criminal one. But with fentanyl here, or at the very least on our doorstep, it is time to assist and protect those who want to keep New Zealanders alive.
I've written in this space before of my admiration for Know Your Stuff, a small community group that chemically tests partygoers' drugs at New Zealand music festivals.
The group has been operating in a bit of a legal grey area. It's a quality control programme for a dangerous and unregulated market, where the right information can keep someone alive. With fentanyl on our doorstep, Know Your Stuff wants legal protection.
The new health minister is hesitant. David Clark says even though police have allowed the drug testers to operate, explicitly protecting them through legal measures could be seen as encouraging drug use.
But just as no one who is prepared to experiment with heroin has ever been dissuaded by illegality, festivalgoers have always taken drugs and will continue doing so no matter the law.
And although heroin and fentanyl are probably less likely to be used at music festivals than other party drugs, I can't see why we wouldn't want to give drug users the maximum information about the risks they're preparing to take this summer.
Last year, 30 per cent of the drugs tested by Know Your Stuff had either been cut with something else or were completely different to what the purchaser had been led to believe.
It's better to keep people alive today so they can make better choices tomorrow.