Now we have to go back and re-watch "The Hunger Games" to see where the odds of staying awake were not in Katniss Everdeen's favor.

was recently on "The Tonight Show Starring Jimmy Fallon," and she joined Jimmy and "Last Week Tonight" host John Oliver for a game of "True Confessions." They had to open one of two envelopes -- one containing a true confession from their past, another a lie -- and then try to sell whatever story was in the envelope while the others interrogated them to determine if they were telling the truth or not.

JLaw went first, and her envelope had a pretty juicy "confession": "I once took an Ambien before filming a scene in 'The Hunger Games.'"

She told Jimmy and John it was not before a sleeping scene, or a fight scene, and no one else was around at the time. When Jimmy asked if it was a mistake, she said yes, adding, "I thought it was something else." John Oliver asked, "If this is true, is it going to cause you legal problems with the studio?" Jen answered, tentatively, "Um, well, the movies are done?" John replied, "That's not how the law works!"

So was she lying or not? John made his guess: "It's plausible. It's reckless. I kinda like it. If it's not true, I am going to be very sad." He said it's true. Jimmy took a while but also decided it was true. Jen admitted that it was true. And somewhere out there a producer is having a seizure.

Watch the full seven-minute video for Jimmy and John's "True Confessions":

But John needs to finish that naked Tokyo sauna story!

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The Hunger Games
Based on 49 critics

In a place once known as North America, youths fight to the death in a nationally televised contest. Read More

The Tonight Show Starring Jimmy Fallon
Based on 19 critics

The long-running late-night talk show returns to its New York roots for the first time since 1972 when comic Jimmy Fallon takes over hosting duties, accompanied by his Gr... Read More