Spoiler alert: When Seth Rogen seems super high in, well, most of his movies, he's not (as far as we know). In fact, whether it's vitamin B powder, herbal cigarettes or some other drug stand-in, actors in movies are never really doing drugs.
Perhaps they have done some drugs in real life and have a sense of what it's like to be high, but what if they haven't?
We give you the undeniably greatest actor of his generation: Leonardo DiCaprio.
"Never done it," Oscar nominee DiCaprio told the Los Angeles Times about his experience taking drugs.
Though known for decades as one of Hollywood's most eligible, most party-ready bachelors, DiCaprio, 39, "emphatically" denied every trying drugs, a statement that is even more incredible if you've seen his work in "The Wolf Of Wall Street," which earned him a Best Actor nod at the upcoming Oscars.
Because in that film Leo gives what can only be called one of the greatest stoned performances in recent cinema history. Whether he's supplying a so-wrong straw-full of cocaine to a prostitute's unmentionables, snorting endless lines on his yacht and office or joining Jonah Hill for a epic Quaalude meltdown that should earn him a special Oscar, Leo is great at acting high.
"That's because I saw this stuff literally every day when I was 3 or 4 years old. So Hollywood was a walk in the park for me," DiCaprio explained about the evils he saw growing up poor in Los Angeles. "I'd go to parties and it was there and, yeah, there's that temptation. Hollywood is a very volatile place where artists come in and they essentially say they want to belong. It's incredibly vulnerable to be an actor and also get criticism at a young age when you're formulating who you are. We've seen a lot of people fall victim to that, and it's very unfortunate."
And while there are plenty of pictures, legendary stories and on-screen examples of Leo's love of the drink, he has never been caught in a compromising position when it comes to illicit substances.
So, here are our favorite times Leo made it seem really real:
The "Wolf" 'Lude Crawl
The Basketball Diaries
In 1995's "The Basketball Diaries," DiCaprio played poet/rocker Jim Carroll, eerily capturing the depravity and drug spiral of a promising b-ball prodigy who succumbs to the mean streets of New York.
And in 2000, in "The Beach," he played a world-traveling seeker who joins a group of fellow drop-outs on a secret island where weed is a daily part of the ritual of paradise.