Image Credit: TURE LILLEGRAVEN FOR EWThe Sundance Sesame Street documentary Being Elmo has been leaving audiences … tickled.

The film takes a look behind the scenes at Kevin Clash, the big, tough-looking dude who is the heart, soul, and high-pitched voice behind the world’s most beloved baby monster. The 50-year-old puppeteer’s sense of humor and gentleness is immediately obvious (Elmo just helps channel it), and documentarian Constance Marks goes deep in her film on his inspiring story from childhood Sesame Street fan to one of its biggest talents.

As the theme song goes, “Can you tell me how to get, how to get to Sesame Street?” Through hard work, talent, and imagination, the little boy who dreamed of making people smile with his puppets found his way there, making a little-known character into a global phenomenon.

KEVIN CLASH: I grew up watching Ernie and Bert, and Grover and all those guys. Grover was my favorite, and he’s still my favorite. That was my generation. Now, my daughter’s generation is Elmo.

ENTERTAINMENT WEEKLY: How old is your little girl?

KC: 18. [Laughs] Yeah see, but we still call ’em little girls, right? [To director] You still call yours a little girl.

CONSTANCE MARKS: And mine is 12.

Did she inspire you to do this movie?

CM: I just was in love with Elmo. My husband was a [cinematographer] and he was shooting on Sesame Street and had an opportunity to introduce me to Kevin, and I just had always loved that character. I just thought he was so plucky and funny and different from all the other characters on television. And he had an edge and a humor and compassion. I said, “Who is behind this remarkable creature?”

Did you worry about spoiling the illusion by making this film?

KC: You gotta understand, and you have a child too, so you’ll see — they keep their imaginations for as long as they want to. Let them keep it as long as they want, like Santa Claus or the Easter Bunny. Kids see me as someone who is carrying their friend. They’re not looking at me. Elmo will bring them back to them and they’ll have a conversation. [Laughs] That’ll happen with an adult too.

Constance, what surprised you about the creation of Elmo when you started making this documentary?

CM: Watching Kevin ad-lib without a script. I could do it 24/7. Whenever I see it, he’s just wickedly funny. And it’s joyous and surprising and irreverent and hysterical. It’s a great thing to behold.

KC: I know the character very well, and I know the limitations as far as how far I can go with him. One thing I loved about Jim [Henson] and Frank [Oz, the puppeteer-turned-filmmaker behind Miss Piggy on The Muppets and the creator of Grover, Bert, and Cookie Monster on Sesame Street] is they had that Muppet edge, but we can’t go too far. We can’t work blue. [Laughs] What I always looked forward to doing is ad-libbing. Then you can have a conversation with him about anything and the script doesn’t get in the way.

Has playing Elmo for 25 years changed your point-of-view?

KC: He’s changed my life as far as my success. Has he changed me? No. I still have challenges as a human being. As all of us do. I have weaknesses and strengths and stuff. What Elmo does with me is help deal with the simplicity of life. It’s the same thing as having a child, hopefully. [Laughs] It doesn’t happen 100 percent of the time, because there’s still some crazy people with children out there! But hopefully it does bring you back [to what’s important.]

What was it like for your daughter growing up with a dad who plays Elmo?

KC: I started doing Elmo in ’86-’87. So I did it for years before Shannon was born, but it was wonderful to see Elmo through her eyes.

CM: She thought at one point, when she was really little, that Elmo was her brother. And she knew she could get things from you by telling Elmo about it.

KC: [Laughs, impersonating his daughter] “Hi Daddy, can I speak to Elmo?” “Yeah, yeah, Okay.” [In Elmo’s voice] “Hi Shannon.” “Hi Elmo — listen there’s this new Barbie that I… ” [Laughs] Let me tell you, Shannon has earned many more Emmys than I have with her dramatics … I’d take my Emmy and put it down on the floor. [Applauding] “Oh, you deserve this, girl.”