As a kid, Colin Mochrie never imagined he’d grow up to become one of the most recognizable improvisers in the world. Not that he was lacking self-confidence; it’s just that it wasn’t even an option back when he was living with his parents around 48th and Fraser and attending Killarney Secondary School.

“I’m still having trouble fathoming that I’m working at something that wasn’t an occupation when I was growing up,” the 57-year-old said over the phone from his home in Toronto. “So everything that’s happened has been a bonus. The one thing I’m actually good at and the one thing I really enjoy turned out to be a very nice career for me.”

That’s an understatement. But it’s to be expected from the understated and unlikely comedy superstar. The man came to fledgling fame when he starred in the British series Whose Line Is It Anyway? and then skyrocketed from there when the Americans took it over, spending 18 years with that franchise over two continents. He’s got scads of acting credits since then, but it’s Whose Line that he’s still best known for.

“Yeah, that may be a comment on my acting, who knows?” he jokes. But he does acknowledge that the show gave him his career. Back up from there, though, and it was Vancouver that really got things going for him.

“Vancouver TheatreSports [League] pretty much gave me everything that I have now,” he says. “I learned the basics of improv there, I learned how to work with people, and how to work with audiences.”

Back in 1983, a young improviser named Jay Ono joined the company, a couple of years after Mochrie, and watched the future star in TheatreSports Hamlet and a murder-mystery show called Suspect. Over the next few years, Ono shared the stage with him often, before Mochrie made the move to Toronto.

“Colin was just so great to play with because he was always so humble,” says Ono at the offices of TheatreSports, where he has been serving as executive director since 1994. “Colin’s a great team player. He’s so unassuming that when he improvises, it’s surprising. He just goes off on these tangents or these moments of comedic genius.”

Ono’s duties at the company preclude him from performing as much as he used to, although he tries to get up on-stage a couple times a month. The next times will be on Saturday (August 22) for both the 7:30 and 10 p.m. shows, when Mochrie will be the special guest. (He’s also doing two shows on Friday and a gala on Thursday, featuring a postshow Q & A.)

The gigs will be at the 186-seat Improv Centre on Granville Island, offering fans a great opportunity to see one of the best up close and personal, unlike some of the shows he plays.

With his Whose Line buddies, Mochrie once performed for 10,000 people crammed into an American university gym. “Just trying to hear suggestions was crazy,” he recalls. “But it certainly gets your energy up when you have 10,000 people laughing. But I do enjoy the smaller venues. It feels much more intimate with the audience and the magic up close, just so they can see there isn’t anything we’re doing except taking their suggestions and running with them.”

Mochrie still tours large theatres regularly with fellow Whose Line alum Brad Sherwood, and recently they were part of a reunion of the British show, doing two weeks in London’s West End.

But he’s no comedy snob. The man will play with all comers. He’s constantly working with “the kids” in Toronto’s improv scene, as he calls them, and here in Vancouver he’ll be acting alongside 21 different VTSL players over the five shows, a testament both to his generosity and the company’s deep roster.

“I think a lot of people get stuck in their comfort zone,” says Ono. “Colin will play with anybody.”

That might not be totally selfless on Mochrie’s part. He’s always fighting to make sure he doesn’t make the same choices, which is a difficult proposition after 30 years of improvising, and this helps keep him on his toes.

“There are times where you’ll say something and go, ‘Oh, wait, that sounds really familiar. Either I’ve just stolen it or it’s something I said years ago,’ ” he says. When he works show after show with Sherwood, they’re always trying to come up with ways to avoid repeating themselves. And away from his duo or group tours, he collaborates with as many improvisers as he can.

It’s that hard work and dedication (and a funny bone that doesn’t quit) that’s given this unlikeliest of comedy superstars the nice career he talks about, and the fame that still catches him off-guard.

“I’m a little paranoid anyway, so when people are looking at you and whispering, you’re thinking, ‘Oh, what? Is my fly open?’ ” he says. “It’s still weird. I just do normal things. I do all the shopping because I do all the cooking, and it’s just bizarre when people will stop me and ask for an autograph or something. It’s like, ‘Oh yeah, it’s my job.’ ”

Colin Mochrie plays five shows at the Improv Centre on Granville Island from Thursday to Saturday (August 20 to 22).