Sunny days, sweeping the clouds away, on my way to where the air is sweet – like millions of children who grew up in the 1970s, I can tell you how to get to Sesame Street. It may be 40-years-old, but little about the show has dated: I have it on good authority – two nephews and a niece – that Cookie Monster still gobbles cookies mumbling "Om, nom, nom", Oscar is still grouchy, and Big Bird is still played by the same puppeteer, Caroll Spinney, who has played him since the show began.

For two generations, Sesame Street has introduced us to our first friends, from whom we learned, even as we laughed. We learned to count with the Transylvanian Count, as well as with the hapless waiter who always announced "three... peanut butter... sandwiches" before he fell and dropped them. We learned the answers to Ernie's endless, pestering questions, and that Bert shouldn't roll his eyes in impatience: just like my big sister, in fact. Sesame Street was a pioneering educational TV show, intended to help underprivileged children. But even those of us middle-class kids spoilt for pedagogical choice couldn't get enough of it.

The show's success has led to so many scholarly studies that it is the most-researched show in television history – andto my mind, it is unquestionably the most important children's TV show of all time. It didn't just teach us the alphabet. It taught us tolerance and multiculturalism: the muppets and adults are all different colours, different backgrounds, and all together in the neighbourhood. We learned English, yes – but a little Spanish, too.

It taught us kindness, patience, to believe in each other – and in our friends' apparently invisible friends, like Mr Snuffleupagus (or to give him his full name, Aloysius Snuffleupagus). It taught us to respect curiosity, Ernie's existential questions, and Big Bird's wide-eyed misunderstandings. It taught us that Oscar shouldn't be grouchy, but also to accept that he was unlikely to change.

When I was little, I loved a picture book starring "Lovable, Furry Old Grover", called The Monster at the End of this Book, in which Grover is terrified to learn that there will be a monster at the end of the book, and begs the reader not to turn the page. The curious child keeps going, and they discover together that Grover was the monster all along. When I was six, I called this hysterically funny; now I can call it metafiction, and teach it at university. There is nothing that Sesame Street can't teach you, if you let it.

The writer lectures in American Studies at the University of East Anglia