The Big Bang Theory is a sitcom that has won awards, laughs and the hearts of fans around the world, as well as providing a go-to solution for the Nine Network when it comes to scheduling.

While Jim Parsons, who plays the people-skills-free physicist Sheldon has won many plaudits for his efforts on the show, Johnny Galecki, is equally loved as the other atom required to make up this odd couple scientist molecule. Galecki is used to playing the straight man in comedy, having done so since he first came to prominence as Chevy Chase's son in 1989's National Lampoon Christmas Vacation.

Surprised to be Big ... Johnny Galecki plays Leonard in The Big Bang Theory Credit:Domino Postiglione

How do you feel now that you are more recognisable all over the world?

Yeah, it is a little daunting, but everyone is so nice, all the fans are so nice and I think there is a vulnerability to these characters that makes people almost want to protect us, and we are greeted on the street with such sweetness, it really makes people be much sweeter to us, much more so than we probably deserve as people.