When I was eight, I bought my first puppet. It was a monkey, and I paid five cents for it. I collected some scrap wood and built myself a puppet theatre. I made 32 cents with my first show, which I thought was pretty good, and that’s when I knew I would be a puppeteer when I grew up.

I’d worked on a few different shows before I got the job playing Big Bird and Oscar the Grouch in the first season of Sesame Street, in 1969. I had no idea I’d still be doing it more than 45 years later.

Big Bird is actually a puppet; my right arm is his neck, and my right hand moves his head, with my little finger controlling his eyebrows, moving them up and down to show when he’s thinking. I can change his expression by tilting his head toward the camera at a different angle. My left hand is in the left wing, which is linked to the right wing with fishing wire. I can’t see anything outside the suit when I’m in it, so I wear a little monitor strapped to my chest, which shows me what the viewers see at home.

In the early days, each scene was very simple and I could memorise my lines on the spot, but the show evolved and the storylines became much more elaborate as the years passed, so now I keep my cues and my lines taped to the inside of the costume.

At first, Big Bird wasn’t a major character, and Jim Henson, who developed the characters, said to play him like a goofy yokel from the country. But it felt more natural to me to play him as a child, like a big kid. When I tried it out, Jim and the writers agreed, and soon Big Bird grew into a worldwide superstar. I knew Sesame Street was being broadcast in other countries – 160 of them – but I didn’t know just how big it was until I was flicking through a children’s book in 1972. In the back there were pictures of kids’ cartoons. All the big guys were there: Mickey and Minnie Mouse, Donald Duck and Goofy, and dancing along with them were Big Bird and Oscar. I thought, “Oh my gosh, I’m with Mickey Mouse!”

I met huge stars like Jimmy Stewart, appeared on shows like The West Wing and Saturday Night Live, and sang with legends Michael Jackson and Ray Charles. His agent said to me, “What’s it like singing with Ray Charles for the second time?” and I said, “What, I’ve sung with him before?” It’s easy to lose track. I’ve met eight first ladies, including Michelle Obama, and I found out Barack is my ninth cousin twice removed, although I’ve never met him. Six years ago he sent me a letter for my birthday, saying, “Congratulations on your first 75 years” and it’s still hanging in our front hall. Michelle told me that when her daughters found out they were related to Big Bird, they squealed and danced around the kitchen.

I once got a letter from Nasa, asking if I would be willing to join a mission to orbit the Earth as Big Bird, to encourage kids to get interested in space. There wasn’t enough room for the puppet in the end, and I was replaced by a teacher. In 1986, we took a break from filming to watch takeoff, and we all saw the ship blow apart. The six astronauts and teacher all died, and we just stood there crying.

The show is still huge, especially in New Zealand and Australia, and in South Africa, where they have their own version – they recently ran a storyline to encourage parents to let their children play with kids who have HIV.

I still perform as Big Bird and Oscar the Grouch, but not as regularly as I used to, so I’ve got more time to spend with my wife, and also for painting. I tend to draw Big Bird in situations he couldn’t possibly get into on the show, like snorkelling or windsurfing.

It’s amazing to think that people watch our puppets all over the world, and now a documentary has been made about my life. But I don’t think it’s changed me, I don’t have a swollen head. Perhaps the show keeps me young – I’m still playing a six-year-old even though I’m 81. I guess that makes me the world’s oldest child star.