Jeff Kinney. Photo: The Guardian

Jeff Kinney's journey from failed newspaper cartoonist to creator of the phenomenally successful Diary of a Wimpy Kid graphic novels reads like the American dream.

An ordinary but ambitious boy inherits his father's love of comics. The lad goes to university with the intention of joining the US Air Force but finds he lacks a warrior's soul. He switches studies to computer science and creates a comic-strip character for the student magazine, then spends three years after graduation fruitlessly trying to interest newspapers in syndication until one day, despondent at the growing pile of rejection letters, he starts a journal to shame himself into continuing cartooning - and quitting his video-game obsession.

I'm writing for entertainment, not to impress literary judges. 

Rereading his journal, a light bulb goes off in his head. If his cartooning was too rudimentary, why not simplify his work even further and draw as if he were a kid?

By now a computer programmer for a children's education game website, Kinney spends the next eight years labouring over his Wimpy Kid creation, perfecting its minimalist lines and notebook fonts, weeding out his least-funny ideas and testing the surviving gags on his solemn younger brother, Patrick. Kinney suggests the children's website publish daily entries from the fictional diary to entice return viewers and is amazed by the online feedback.

Two years later, he drops in on a comics convention in New York in the hope of finding a print publisher for the Wimpy Kid, only to find the conference sold out. He considers returning home that day but has tickets to see Billy Joel play Madison Square Garden.

So he stays and ultimately presses a 20-page pencilled submission into the hands of specialist book publisher Abrams, which signs the Wimpy Kid to a multi-book deal. Both parties later ponder how their mutual fortunes turned on that serendipitous moment in 2006.

''I feel lucky I didn't become that newspaper cartoonist I wanted to be because in the US so many newspapers have suffered circulation declines and some have folded,'' Kinney says. ''What's fun about being an author is I reach a much bigger audience and there is something special about launching a book you've penned.''

With a ready-made online audience, Diary of a Wimpy Kid made The New York Times bestseller list within three weeks of its release. Kinney has not been off the bestseller lists since. Time magazine named him one of the 100 most influential people in the world in 2009, a distinction he first dismissed as a joke but now offers as evidence of fame's ''crazy ride''.

Weeks ago, Kinney and his wife, Julie, and sons, Will and Grant, were invited to the White House to shake hands with the President. Before that, he had been feted by international publishers at the Bologna Children's Book Fair, where he announced a seventh Wimpy Kid book would be published globally on November 14.

''It feels like I'm living another life. I'm playing at it, that it's not my real identity,'' he says.

Described as Seinfeld for kids, the Wimpy Kid is about the well-intentioned but socially inept foot-in-mouth protagonist, Greg Heffley. Kinney's 12-year-old narrator is a self-absorbed nerd struggling to fit in at school, anxious about his popularity, his ability to outrun bullies and his lack of chest hair. Drawn slump-shouldered with a round face, no eyebrows and a three-strand tuft of hair, the Wimpy Kid vacillates between overconfidence and bumbling insecurity.

Greg is no role model but his flaws are realistic and common to that age group, the author says. Heffley's loyal friend is Rowley Jefferson, who acts as the counterpoint to Greg's moral failures. A delinquent elder brother, Rodrick, a toddler brother, Manny, and Fregley, the cheerful schoolyard pariah, make up the Wimpy Kid's neighbourhood.

''Greg's in a rush to grow up, as most kids are,'' Kinney says. ''Rowley understands that being a kid is a good thing and he has feelings that are age-inappropriate. Greg is a person not fully developed. He is the person being formed in front of our eyes.''

Humour has long driven children's reading habits, from Roald Dahl's twisted tales to Andy Griffiths's bum jokes and Kinney's schoolyard irony. Even teachers and librarians recognise that the Wimpy Kid's constituency includes reluctant readers, drawn to the mix of text and cartoons.

By describing the unwritten rules of the playground, the hierarchy of classroom tribes and the complexities of boy-girl interactions in Greg's unpolished and ungrammatical ''hand'', Kinney creates a world familiar to most parents, too. Where The Simpsons is anarchic and deviant, celebrating family dysfunction and subverting middle-class values, the Wimpy Kid was conceived as a quaint reminiscence for Generation X before Abrams decided it would be best marketed to their kids. A single touch of a mouldy cheese slice in book one renders the Wimpy Kid persona non grata, like the invisible contagions of girls' germs or boys' germs. Fleshed out, the Diary of a Wimpy Kid films have that slightly knowing, nostalgic feel of The Wonder Years.

Kinney sees himself as a gag writer rather than a social commentator, and typically sets about writing the jokes first before figuring out how to string them in a narrative. It's not literature and it doesn't pretend to be.

''If there is any message in the Wimpy Kid books, it is that reading can be and should be fun. As an adult reader, when I see an obvious moral lesson to be taught I run in the other direction … Kids can sniff out an adult agenda from an early age. I'm writing for entertainment, not to impress literary judges. I hope kids get a kick out of it and that's the beginning and end of it.''

Early in the series, Kinney decided to keep the Wimpy Kid ''frozen in amber'' on the verge of adolescence, like Charlie Brown, destined never to blow out candles on a birthday cake.

''I was struggling for a while when I first started a Diary of a Wimpy Kid,'' Kinney says. ''I thought eventually the story would have to end because Greg would grow up and leave middle school [late primary and early high school] and I'm not interested in the problems of late adolescence. I was mistaken in thinking of him as a literary character and not a cartoon character. The key to any good comic strip or television sitcom is to reset the board at the end of the episode because people like familiarity.''

Growing up in Washington DC, in a tight-knit family, his own stable and unremarkable childhood has served his writing well. His father was an analyst for the navy, his mother a teacher. Kinney's worst transgression was to duck off to the nearby creek to catch tadpoles when his father dropped him off at the pool for swimming lessons. ''I'd race back and jump into the pool and my dad wouldn't know any different.''

Is Kinney the original Wimpy Kid? ''Well, I wasn't very outdoorsy,'' he says. ''And I was pretty skinny.''

When he's at home in Plainville, Massachusetts, he does ordinary-dad stuff, pushing his sons on the backyard swings while the family dog plays underfoot and his wife, Julie, inline skates in their cul-de-sac. Kinney is also a Scoutmaster and coaches his sons' basketball, soccer and baseball teams. He wouldn't want to raise sons Will and Grant anywhere else and is so attached to this patch of middle America that he bought the house next door, converting the family room into his study so he can work when the children are asleep.

The six Wimpy Kid books - including a movie diary and do-it-yourself book - have sold almost 80 million copies, with Australian sales topping 2 million. Kinney has enough ideas to keep him busy with many more books and possibly a television special. There's a third Wimpy Kid film in production, which he predicts will be the last, since the cast are growing up fast. He's keeping a close watch on J.K. Rowling's e-book and fan-games platform, Pottermore, to see if the Wimpy Kid could live in cyberspace.

Despite an apparent lack of ego, Kinney has lost none of the ambition that kept him pressing on when no one else cared for his talent. He hasn't given up his day job as the creator and designer of the interactive children's website Poptropica, of which he is immensely proud. It is not that Kinney is insecure but the author thinks of himself as a man who has won the lottery twice, with his website and books.

''I'm overwhelmed and overworked right now, and the success of the Wimpy Kid robs me of time with the family. I've taken on far too much but I'm satisfied. Not everyone gets to live their dream.''

The Diary of a Wimpy Kid series is published by Puffin. Jeff Kinney is a guest at the Sydney Writers' Festival. See