Colorado’s former-governor-turned-presidential-candidate John Hickenlooper gets his fair share of pot questions on the campaign trail these days.

Voters in early states like Iowa want to know how it’s working and whether Denver really has enough marijuana revenue to pave its streets with gold. We talked to Hickenlooper on the eve of 4/20 about marijuana, what he tells his teenage son about smoking and where he comes down on legalization.

Here’s what he said, edited for clarity.

Let’s talk about election night 2012. You’d opposed legalizing recreational marijuana, and then voters decided 55-to-45 to do it. What was your first thought?

You know, I felt the same way I did when I got the call that Denver was going to host the 2008 Democratic National Convention. (A mixture of excitement and responsibility.) I had been opposed to it (marijuana, not the DNC). I was concerned about what it might do to teenage consumption; more people driving while high. But I also grew up in the ’60s.

There was part of me that felt, that always wondered if it was treated the same as alcohol. If there was a campaign to educate teenagers about the risks of high THC marijuana. If there was a better system out there waiting to be created.

Now that you’re running for president and talking to voters in different states, what do they think about Colorado’s marijuana experiment? Is there anything they get wrong?

Oh my gosh, it’s amazing. I used to think that Paul Bunyan was a pretty far-fetched legend. There are all kinds of stories about what we did in Colorado, and how much money it is making in the state. And how we are going to pay for early childhood education for every 3- and 4-year-old. There are these over-the-top, insane legends.

I think every parent of small children in Colorado knows that preschool isn’t free. Beyond what voters in other states get wrong, what do they want to know about legalized cannabis? 

They ask me what our mistakes were. We obviously made mistakes. We still have a modest black market … Andrew Freedman (who worked as Colorado’s first marijuana czar), he thinks we have the smallest black market of any state. People want to know what recommendations I give to other states; what do I tell other governors … The real question they want to know is if it works.

Do you tell them that legalized marijuana works in Colorado? Did we build that better system?

The things that we were most worried about didn’t happen. The spike in teenage consumption, for example. There was this big federal study (released in June 2018) showing a significant decrease in teenage consumption in Colorado … We spend more of a percentage in per capita terms, we spend more money on youth prevention than any other state. That’s often one of those lessons I try to teach other governors: Build the mousetrap the best you can right from the start.

What about your own son? Has the messaging worked on him? He’s about the same age you were the first time you say you tried marijuana.

I have told my son many times. I have told him candidly many times that high THC marijuana when your brain is growing rapidly has a high probability of diminishing your long-term memory. You’re at risk of losing a little sliver of your long-term memory, even if you only smoked this pot once a week.

(Long-term memory) is how society generally, that is one of the main ways they measure your intelligence, your IQ. That’s the one part of your brain almost more than anything else that you don’t want to lose.

I bet you anything he’s probably tried pot. He’s a teenager. What can I say? I watch him closely, though. When he comes home at 11 (p.m.) or 12 a.m., I’m talking to him; I’m peering into his eyes so close to see if they’re dilated that he can smell my breath.

It’s probably a different conversation than you imagined having with him when he was born. Marijuana wasn’t legal then.

When we first passed it in 2012, I talked to dozens of teenagers, high school students … I asked how hard it was to get pot and would legalization change their approach to smoking it. None of them thought it was going to be any easier to get it. One of them even said if you do it right and get the taxes right and you get rid of the black market, you will actually make it harder. … Drug dealers don’t care who they sell to.

In those first months of legalization, did you ever worry the federal government was going to stop Colorado?

That was certainly a problem, an anxiety and a concern. … I explained (to the Obama administration) what we were doing and why we were doing it. They were sympathetic to the fact that our voters passed it 55 to 45. It took a certain amount of diplomacy with the Obama administration to let us become a laboratory experiment.

Did that feeling come back when the Trump administration, under former Attorney General Jeff Sessions, rescinded its memo that protected states where medical and recreational marijuana is legal?

They were definitely firing a shot across the bow. We went to see him right after he took office. … He was very direct and very blunt (no pun intended). He said, “I don’t see how smoking or consuming marijuana in any way makes us a better country or a stronger country. I recognize the situation you’re in, and I also recognize we don’t have the resources to fully address the illegal activities.”

And I can quote him, he said, “We recognize that we have higher priorities: heroin, methamphetamines, fentanyl.” … There was a recognition, there was a tacit sense that they would let us do this. There was just this kind of sense that they didn’t have the resources to come in and take over.

Last question: Since you’re running to be president, would you sign a bill decriminalizing marijuana at the federal level?

Yeah, absolutely. I would support that. … A lot of states, certainly at the minimum, want to legalize medical marijuana. I think 33 states already have. That’s two-thirds of the states, which should trigger something.

Let’s get the FDA involved and research what are the different medical conditions where it’s effective and what are the side effects. … Let’s get the Department of Agriculture involved. … I think that there is a whole raft of things the federal government should do.

If it’s true that states are the labs of democracy, and I think it’s true, and one of the keys to a successful country, let’s make it possible.