LOS ANGELES -- When Sonia Manzano was cast as Maria on "Sesame Street," she was convinced her stay would be short.

"It had already been satirized by 'Saturday Night Live' and the Muppets had already been on Johnny Carson," she explains. "In my mind, once you'd done that, how much longer could a show last?"

Pretty long, to be honest.

Nov. 10, "Sesame Street" marks 40 years on PBS.

And Manzano? She's still residing at television's most famous address.

"I feel like I blinked and it's 40 years later," says Manzano, who plays Maria. "It's like going off to college."

In the '80s, Manzano's character had strong storylines -- she fell in love, got married and gave birth. Now, she spends more time as writer on the series. But that's OK. "Sesame Street" has lasted this long, she says, because it constantly changed.

"I loved Mr. Rogers but he wouldn't change his format. As a result, people didn't know he was making new shows. You've got to change. You've got to keep up with society."

"Sesame Street" has, its producers say.

When they wanted to show how kids deal with new situations and new people, they added Abby Cadabby, a fairy who could deal with social issues. After extensive planning, research and modeling, they went looking for someone who could voice her.

Enter: Leslie Carrara, a veteran puppeteer with an education in child development. Working on "Johnny and the Sprites," a Disney Channel series, she had experience with a similar character -- Ginger. She auditioned for Abby and won the role. It was, she says, a dream come true. "Everybody there is so supportive and so loving," she says. "We know we're championing young people. The other thing is there's this unspoken joy in the way that kids connect with our characters. Never underestimate the power of joy."

Or hope.

David Rudman grew up watching "Sesame Street" and vowed he'd one day work on the show. Flash forward and, in 1985, he became a member of the cast. Today, he's Cookie Monster and Baby Bear, two key characters.

"I started working for the Muppets right out of high school. I was really into art and sculpture and I just loved watching the Muppets. They were like these sculptures on television, these pieces of art."

Working first in the workshop, building Muppets, Rudman got an education in all this furry. Jim Henson then asked him to assist puppeteers and do background work. When Frank Oz (Henson's creative partner and the creator of Cookie Monster, Miss Piggy and others) couldn't be around on a regular basis, officials started looking for a viable replacement. Muppeteers auditioned; Rudman got the job. "Frank decided who he wanted to do it." Rudman started the gig 10 years ago. Even better? "I can do all these characters but no one knows who I am. No one says, 'Hey, there's Cookie Monster.'"

His four children, however, love the association and don't hesitate to brag about their dad.

Initially, he admits, "I felt like I was just a guardian of the character. But as I got to do it more, I felt a real bond."

Now, because Rudman's available, Cookie gets more screen time -- a plus for fans.

Interestingly, there aren't dozens of Cookie Monsters in the Muppet Workshop. Since the '70s, Rudman says, there have only been two. "The more worn they are, the better they look on television. New characters almost look like toys because they're so clean and fuzzy. When they have a little rattiness, they feel almost real."

While writers help put words in the Muppets' mouths, it's up to the puppeteers to give them life.

"Sometimes a character can reach children in ways you can't imagine," Carrara says. "We did the Hurricane Katrina tour and it was amazing. These kids needed to feel embraced and we brought that to them. The amount of love we felt on a daily basis was amazing."

The future?

"Sesame Street" could go on another 40 years, Manzano says. "It'll just change form."

Will she be a part of it? "Oh yes," she says with a laugh. "I'm 152 years old today. I'll stick with it."