Michael Cera's accomplishments within Hollywood are unique. Granted, he gets type-casted frequently to play awkward nerdy characters like Adam Sandler gets type-casted for rambunctious comedies but he doesn't seem to mind. He doesn't take himself too seriously and enjoys a good laugh.
He's sitting on some stairs with headphones in, listening to Gorillaz while maintaining a nonchalant demeanor. He rarely has any angry outbursts, aside from when he wants to joke around with directors and the crew of the movies he's worked with. He's not an aggressive celebrity that acts like a complete douche behind closed doors. He's one of the more laidback actors in his field.
The music is calming, and he has a few hours until his next scene for a project he needs to shoot. He's civil but, like everyone, does have his limits. He isn't paying attention to the world around him until he sees you near him. He takes his headphones off and speaks. "Hey there, you're a fan, right? Or are you just some random citizen passing by? I'm Michael Cera, and it's nice to meet you." How do you proceed?