HOST EXTRAORDINAIRE: With Will Smith on The Tonight Show Starring Jimmy Fallon
Lloyd Bishop/NBC

The #hashtag video Justin and Jimmy made last year quickly went viral and scored a spot on the YouTube Rewind 2013 Top 10 list. “Hashtag kind of changed my life for a bit,” Jimmy says. His least-favorite hashtag? “#NoFilter makes me laugh because what are you, Annie Leibovitz? You took that photo with your iPhone. Also ­#sorrynotsorry makes me laugh. Like someone puts, ‘What was she thinking with that dress!? ­#sorrynotsorry.’ ”

Jimmy didn’t have any plans beyond SNL, where he made viewers laugh from 1998 to 2004, after getting his start through stand-up comedy and improv shows. He thought about being a computer programmer — he went to college for it and once wrote a program for videocassette rentals. He thought about being an IBM worker — like his dad, who he said was always happy. He even thought about being a postal worker — suggested by his supportive-yet-practical parents if comedy didn’t work out. But he says, “My ultimate dream was to be on SNL. Every time I cut into a birthday cake or blew out a candle, the wish was to be on SNL. Then after that, I didn’t know what I wanted to do.”

Fortunately, Lorne Michaels, the executive producer of SNL, Late Night and now The Tonight Show, did know what Jimmy should do. Five years after SNL, Lorne

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— who had mentioned to Jimmy about taking over Late Night right after Jimmy decided to leave SNL and try his hand in film — called, Fallon recalls, and told him, “ ‘Remember that idea I had? You still want to do that?’ and I was like, ‘Yea!’ At the time, my movies came out and they did OK, but they didn’t do that well. It wasn’t like they were knocking on my door in Hollywood. So, I was like, ‘Let me ask my wife because now I have a wife.’ She said, ‘Jimmy, even if it flops — even if it doesn’t work — you’re one of three people: David Letterman, Conan O’Brien and you. What a great list to be on.’ ”

Then he and Lorne had to sell NBC on the idea. Jimmy says conversations got to a point where Lorne gave the network an ultimatum, saying: “ ‘Look, if you don’t want Jimmy, then I’m out. Get a different person to produce it because that’s my choice: Jimmy.’ I’ll never forget that,” Jimmy says. “He totally stuck up for me.”

This September, Jimmy will turn 40. “[Chef] Mario Batali has the same birthday, so maybe we’ll have a joint party,” he says. “Other than that, it’s just a number to me.”

His appearance — and certainly his energy level — haven’t changed much since he became the new kid on the SNL block 16 years ago. And they’re not likely to disappear anytime soon with his shiny new gig at The Tonight Show. “In the weirdest way, I’m getting to that age where I’m growing up with my fans,” he says. “I’ve been around for a long time, which I never thought that I’d be, but in 1998, when I started on Saturday Night Live, I was 23. Now I’m 39.”

On my way out, he offers me a pink ball. “If you’re ever in a bad mood, just do this,” he says, bouncing the ball. “You just throw it or bounce it. There are no rules to a ball. It’s just fun.”

Just like you, Jimmy. 

JENNIFER BIRN is a pop culture junkie living in Los Angeles. She’s written for periodicals ranging from Maxim, Details and In Touch to The Arizona Republic and the New York Daily News. She’s currently working on a novel with former NFL star Dhani Jones.