Colorado Gov. John Hickenlooper, chairman of the  National Governors Association, listens as Vice Chairman  Gary Herbert, Utah’s governor, speaks at the National Press Club in Washington on Jan. 6 outlining the governors’ collective priorities for 2015. (Manuel Balce Ceneta/AP)

One year after his state became the first jurisdiction in modern memory to legalize and regulate marijuana, Colorado Gov. John Hickenlooper (D) says he’s overcome some of his initial anxieties, but remains concerned about youth smoking.

“If you’d asked me the day after the election if I could magically change the voters’ returns around and voted it down, I probably would have said yes,” Hickenlooper said  Tuesday when asked by The Post whether he had concerns about the law.

Though he viewed the War on Drugs as a failure, Hickenlooper had trepidations about legalizing without guidance or federal support. But now, he said, the industry is “in almost every case” well regulated and abiding by the law. But anxiety remains.

“The concern that we still have — that I still have — is whether young people will view this legalization as in some way saying to them that marijuana is safe,” said Hickenlooper, who was answering reporters’ questions following his State of the States address as chairman of the National Governors Association. “And literally every neuroscientist that I have talked to is very concerned that … [among kids] even once a week you can permanently diminish long-term memory.”

Children may still not be aware of that fact, he says, but the state is launching a $6 million education campaign, he added. That campaign — titled “Good to Know” — seeks to educate both adults and children about the harms of marijuana. The new campaign, announced this week, is a successor to the previous “Don’t be a Lab Rat” campaign, which sought to do the same.

“Just because it doesn’t seem to have these negative effects on adults, that does not mean that we should in any way make it easy for kids to get it,” Hickenlooper said.

But legalization does offer benefits by eliminating the black market, he said. In fact, over the summer, state officials conducted compliance checks at 20 recreational marijuana dispensaries in Denver and Pueblo and none sold the plant to children.

“Drug dealers don’t care who they sell to,” Hickenlooper said. “Whereas, if we’re able to eliminate the black market, we will have a much more secure system and make sure kids don’t get access to marijuana.”