“There’s this idea that marijuana just appeared on January 1, 2014 and all of a sudden everyone is going to be using marijuana and not going to work,” says Christian Sederberg, a Denver-based attorney at Vicente Sederberg LLC and one of the key members of Colorado’s Amendment 64 campaign to legalize cannabis. “These are adults. They make decisions. They’ve been using marijuana for a long time and now they’re buying it from a taxed and regulated store.”

It’s been over 18 months since Colorado became one of the first states to legalize marijuana. Though opponents of the measure predicted doom and gloom scenarios, the end of pot prohibition has not resulted in apocalyptic disaster.

In fact, the legalization of cannabis has been a boon to Colorado financially with an expected one billion in sales by 2016 and $40 million in excise taxes to be placed in state coffers.

“No taxes or anything are going to be a panacea. But what it is though is $60 to $100 million at the state level. That’s real money,” states Sederberg.

That’s not to say that legalization hasn’t come with it’s challenges.

One of the unforeseen areas where Colorado faced problems was with edibles—an issue illustrated in Maureen Dowd’s now famous (and highly mockable) editorial where she recounts her bad trip on edibles. The New York Times also reported that just after five months of legal sales, Colorado hospitals reported an increase in the number of children and adults becoming sick from eating edibles (the same article also notes the lack of hard data on the topic).

“The biggest challenge with edibles is not the marijuana,” says Sederberg. “The onset takes time and so people will consume what they are told is a serving…and then it doesn’t work for a while. So then they’ll take another one…and they end up overconsuming.”

The state has responded to such incidents by clarifying regulations on serving sizes and packaging. Colorado now requires that each edible serving size contain no more than 10 milligrams of active THC. The amount of active THC must also be clearly marked on the product and individual edibles must be easily separated into single serving sizes.

Sederberg notes that one of the main reasons for the popularity of edibles is due to the fact that there are no legal spaces to consume marijuana publicly.

“There’s no place to use in a social environment,” says Sederberg. “We really need to make a space for people to consume in a public environment and to be social just like you are with alcohol.”

Sederberg and other legalization advocates are pushing for a November state ballot measure that would create public environments where people could use cannabis socially.

As Colorado refines their regulations, a handful of other states—including California, Nevada, Arizona, Massachusetts, and Maine—could legalize marijuana in 2016. What can they learn from the Colorado experience?

Sederberg stresses the importance of collaboration in the policy making process. “The Colorado model is the work group. It’s the collaboration,” says Sederberg. “You have to listen to all sides. We’ve gotten some very good ideas from people that were our opponents who are not our opponents anymore because they saw that we are working at making it better.”