(NOTE LANGUAGE) Justin Timberlake is considered to be a "good guy" — one of the nicest entertainers around.  But he's got a dark side, as he reveals in the new issue of GQ magazine, which has named him Man of the Year. "Sometimes, I just want to f***ing kill everybody," he tells the magazine.

Justin's harsh words come in reaction to the bad reviews he received for his latest movie, Runner, Runner,including an article in Variety that suggested he simply stop acting.  "The movie didn't do well at the box office, so I should quit?  Hold on a second," he rants. "If I was somebody else, you wouldn't have said that. I have the number one album this week, and I shouldn't have released it? Come on, man….it just shocked me because, like, you're trade magazines. None of your opinions count. And by the way, none of you can do it.”

"Sometimes I find it funny that I've been able to acquire the patience it takes to be kind to people in our business," he continues. "Because sometimes I just want to f***ing kill everybody.”

Later in the interview, Justin explains that the reason he ranted is because he's "not cool."  "Being cool,” he explains, “is about keeping your blood pressure steady. So no. Don't be cool. Be passionate. Be dedicated. Be tenacious. Be uncompromising. Be pissed. Be happy. Be sad.”

"I've made a career out of doing things that I should not be doing. I wasn't cool about it,” he tells GQ. “Because being cool would have meant I passed up on those opportunities. If you do that, it's because you're afraid. And what are you afraid of?”

Justin also reveals his pre-show rituals in the article, which include stretching, meditation, lying on an inversion table and then dancing to get his heart rate up.  And finally, seconds before he steps on stage, he says, he has a shot of tequila. His own brand, of course.  “I want my circulatory system on every level to be firing, right when I walk on that stage,” he says. "I want to feel the blood all the way to my fingertips. I want to feel hot."

Read the entire interview in the December issue of GQ magazine.