You can hear that "Sesame Street" is turning 40 years old Tuesday but it's only when it's put this way that it really sinks in.

Earlier this year Time magazine pointed out that Barack Obama is the first president young enough to say he watched Sesame Street as a kid.

The show can put that feather in its hat as it kicks off its new season Tuesday, 40 years to the day it first premiered on Nov. 10, 1969.

Since that time all it's done is revolutionize the way children are taught, introduce a vibrant cast of characters beloved by millions and tackle the hard issues parents often don't know how to broach with their kids.

The show broke new ground in November 1983 with the way it dealt with the death of Will Lee, who had portrayed kindly store owner Mr. Hooper since the first episode. Rather than ignore the issue or sugarcoat it, the show's creators used Lee's death in December 1982 death as a way to teach young viewers about death as a natural part of life.

It also broke new ground in introducing Kami, the world's first HIV-positive Sesame Street Muppet, on "Takalani Sesame," the South African version of show, in 2002. That year also saw Elmo go before the Education Appropriations Subcommittee to urge more spending on music in schools, becoming the only puppet to have testified before Congress.

There is also a joint Israeli-Palestinian-Jordanian project, called "Sesame Stories," which was created with the goal of promoting greater cultural understanding.

It's global reach doesn't end there. There are more than 20 original and localized co-productions of "Sesame Street" including "Galli Galli Sim Sim" in India, "Hikayat Simsim" in Jordan and "Plaza Sésamo" in Mexico.

More than 440 celebrities have appeared since Carol Burnett and James Earl Jones became the first two guest stars in 1969. The group now claims Robert De Niro, Richard Pryor, Stevie Wonder and, most recently, first lady Michelle Obama, who appears in the 40th season opener, among its members.

Caroll Spinney, the 76-year-old who has brought Big Bird and Oscar the Grouch to life for the past 40 years, knows first hand the impact the show has had on its viewers.

"I get wonderful letters from children," Spinney recently told The Associated Press. "'Dear Big Bird, you're my friend. Please come and play with me. How about next Thursday?' That was a beauty. And another one was 'Dear Big Bird, I watch you every day and I wish you'd come and play with me. You could stay. I just got bunk beds and you can have the top.'"