Canadians openly rolled, smoked and vaped legally bought weed for the first time Wednesday as a seismic cultural shift ushered in a new era of how cannabis -- and cannabis users -- are regarded across the country.

The pungent smell of marijuana hung over dozens of people gathered along Montreal's boutique-lined Ste Catherine Street, where hundreds would-be patrons stretched around the block in front of a government-sanctioned pot shop and cheered when doors opened.

Some among the giddy crowd posed for photos and cheerfully demonstrated joint-rolling techniques to reporters.

"It's pretty magical," said 39-year-old Hugo Senecal, who showed up with Corey Stone at 3:45 a.m. to be part of what they called a historic moment.

"It's like Christmas, New Year, my birthday and Easter all in one day. For a stoner it's kind of a good moment."

The 32-year-old Stone said he hoped legalization would help dissipate some of the stigma around cannabis, especially in a province that has some of the most restrictive laws around usage, possession and promotion in the country.

"You can see it from people walking by," he said of the disdain that lingers for some. "Some are smiling, but some are shaking their heads."

In Toronto, an early morning "wake and bake" on trendy Queen Street West drew a handful of stoners to an "End of Prohibition Party" where they smoked and vaped openly on a cafe's back patio.

Bob Marley tunes played in the background as people lingered next to an outdoor firepit and watched a glass artist -- who described himself as a "bongsmith" -- craft an ornate pipe from molten glass.

Robin Ellins, co-founder of the pot culture shop dubbed the Friendly Stranger, said his day-long plans of giveaways, discounts and demonstrations were the culmination of "years and years and years of hard work."

He believes the marijuana milestone will "legitimize" a flourishing cannabis culture that had long been forced underground, potentially broadening its appeal to new users.

"We spent the last quarter-century working very hard every day in order to make this day happen, and it's finally here," said Ellins.

"It's been a lot of work. There's been hundreds of 18-hour days over the years, but to actually see this change happen in Canada, it's a monumental event. This is a once-in-a-lifetime event. We've taken 100 years of prohibition and put it behind us, and now we're starting a new journey."

In Halifax, customers browsing a pristine downtown shop described a clinical atmosphere that nonetheless offered a liberating experience. Afterwards, buyers took their brown-bagged purchases two blocks over to an outdoor area next to a car parkade dubbed the "toking spot."

"I, a little bit, hope my grandmother sees this, but I mostly don't," said Connor McKechnie, a university student who lit a pre-rolled joint in front of a national television network audience.

"So many people have fought for so hard, for so long and now all their efforts have come to fruition and now I get to enjoy this."

The giddy events followed late-night celebrations Tuesday in which revellers rang in the new era with marijuana-fuelled cheers, honking horns, bar lineups and smoky sidewalks in downtown Toronto.

Hundreds rang in the new era with a New Year's Eve-style "bud drop" at one nightclub, where a massive doobie dropped from the ceiling at midnight.

Longtime advocates touted changing mores and greater acceptance amid mainstream society, bolstered by unrelenting hype from entrepreneurs heady from the possible green rush of a budding market.

But while many welcomed the new regime, others feared fallout from legalizing what some opponents consider a "highly potent" substance.

Canadian members of the United States-based group Smart Approaches to Marijuana were set to hold a news conference in Vancouver to announce a watchdog group and website "dedicated to exposing marijuana industry harms."

University of Guelph sociology professor Andrew Hathaway adds that many advocates are also unhappy with aspects of legalization, complaining that new regulations amount to "prohibition 2.0".

Along those lines, another protest is planned on the steps of the B.C. legislature in Victoria by cannabis activist Dana Larsen who is concerned by lack of access to marijuana due to restrictive legislation.

Hathaway notes there are a slew of uncertainties over legal, workplace, health and social implications.

There will be bumps along the road, he allows, but says the significance of Canada becoming the first G7 country to legalize the drug is big.

"First gay marriage and now legalizing cannabis," he says, noting that in contrast so much of the rest of the world is shifting towards the right in politics.

-- With files from Adina Bresge in Toronto, Michael Tutton in Halifax, Elizabeth Leighton in Vancouver and Morgan Lowrie in Montreal