Carol Burnett on Turning 90 — and Cherishing Her Hips and Knees: 'I Still Feel Like I'm About 11'

Carol Burnett has been making audiences laugh for decades, picking up six Emmys, six Golden Globes, one Grammy and a Kennedy Center Honor along the way. On April 26, she'll reach another milestone — turning 90.

"I can't wrap my head around it," Burnett tells PEOPLE in this week's issue. "I still feel like I'm about 11, but I'm amazed. It sure went fast. But I'm glad because I've got all my parts — got my hips, I got my knees and I've got my brain, so I'm happy about that."

NBC will commemorate the occasion with a two-hour special on Burnett's birthday featuring guest stars including Amy Poehler, Cher, Ellen DeGeneres, Julie Andrews and Steve Carell. Carol Burnett: 90 Years of Laughter + Love will also include performances from Bernadette Peters, Billy Porter, Jane Lynch, Katy Perry and Kristin Chenoweth.

As a kid growing up in Los Angeles, "I used to pretend to be on a radio show," Burnett recalls. "I would yell out the window, 'Now ladies and gentlemen, we have a young girl who is going to sing here without any musical accompaniment. One time, a man next door said, 'Will you turn that goddamn thing off?' And I thought, 'I'm a hit. They think it's real.'"

The Carol Burnett Show star admits she didn't discover her knack for comedy until she was in college.

"I was pretty much of a quiet student all through grammar school, junior high and Hollywood High," Burnett says. "I would kid around with my friends, the neighborhood kids, stuff like that. But I never really thought about it until I got to UCLA and I was in an acting class. A lot of the kids at the class were doing heavy, dramatic stuff and I thought, I can't do that. So I picked something light and they laughed. That's when the bug bit."

Burnett says that that makes her a "late bloomer" since "so many performers who started when they were 3 and 4 and 5 years old."

She eventually found international fame, but not without facing a few obstacles. "It was some local television show in New York and I got up and I belted out a song and the emcee that I was auditioning for said, 'You're too loud for television,'" Burnett recalls. "I disagreed."

So did audiences. She headlined The Carol Burnett Show for 11 seasons and Carol & Company for another two, starred as Miss Hannigan in 1982's Annie and had memorable roles in All My Children, Fresno, Mad About You and most recently, Better Call Saul. She's still working, appearing next in the upcoming Apple TV+ series Palm Royale.

Burnett simply wants her legacy to be that "I made people laugh, made them feel good when they might have been down," she says. "In my fan mail, many say it was the only time the family would get together, to watch and laugh. And that sometimes they were lonesome and were cheered up by our show. That's a good feeling."

For more on Carol Burnett, pick up the latest issue of PEOPLE, on newsstands Friday, or subscribe here.

Carol Burnett: 90 Years of Laughter + Love airs April 26 at 8 p.m. ET on NBC and streams on Peacock the next day.

Watch the full episode of People Cover Story: Carol Burnett below