IT WAS always the same old trick. Lucy, smiling innocently, would hold a football for Charlie Brown to kick. For nearly 50 years, she would convince her hapless, moon-faced friend to ignore precedent and trust her. “I'm a changed person,” she would say. But at the very last moment, she would always yank the ball away, sending him flying through the air and on to his back with a thud. A misunderstood boy in a hostile world, Charlie Brown would just sigh. Readers of the “Peanuts” comic strip, who ultimately exceeded 355m, could not get enough of these neurotic, melancholic children.

“Aren't all kids egotists? And brutal?” asked Charles Schulz, the man behind the first mainstream comic strip ever regularly to use the word “depressed”. Schulz acknowledged in 1964 that “maybe I have the cruellest strip going.” But Americans responded to these little characters with big heads, finding humour in their disarmingly spare meditations on loneliness and resignation. “Peanuts” became a $1.2 billion industry and Schulz a national treasure, praised for his simple wisdom and Midwestern sensibility. He drew every one of the 17,897 strips by hand himself.

But Schulz—“Sparky” to his friends—was far more complicated than that, according to a lively, engaging new biography by David Michaelis. Raised in Minnesota, the only child of stoic, uneducated immigrant parents (German and Norwegian), he was an awkward boy and an unhappy man: shy, lonely and haunted by anxieties. He could be witty and kind, but also competitive, righteous, needy and prone to bear grudges. He yearned for approval and assumed he was being rejected. His mother's death, when he was 21, was a loss he never seemed to recover from. “He always felt that no one really loved him,” a cousin observed. “I don't think I can ever be happy,” he announced to his first wife on their honeymoon. (“Good grief,” she surely thought.)

Drawing was his retreat. Despite his insecurities, he knew he was good, and his ambition was to have a comic strip of his own—at a time when the “funny pages” were the country's great popular entertainment. He learned the tricks of the trade through mail-order art lessons. He later became a teacher at the same art school, where he met some of his closest friends (including a bumbling chap named Charles Brown). He spent his 20s living with his father, hunched over his drafting table, collecting rejections from newspapers—and the few women he plucked up the nerve to talk to. Cartooning was a sort of revenge.

Schulz never liked the name Peanuts, which was his syndicate's idea, and he was never especially fond of children. He drew them because “they were what sold”. But these tiny characters were a clever Trojan horse for his more adult themes. The strip, Mr Michaelis writes, “was about people working out the interior problems of their daily lives without ever actually solving them.” “Peanuts” let Schulz harness his melancholy and channel his conflicted feelings.

Though the author never met the man, he had the help of Schulz's family and full access to his papers during his six years of research. But some of Schulz's children (he had five) and his second wife have spoken out against this portrait of a dark and unhappy man. “This was the man I found,” Mr Michaelis responded. “To their children, fathers are always heroes.”

As he was dying of cancer in 2000, Schulz, aged 77, was still talking about getting even with the bullies of his youth. Dictating his final message to his readers, the multimillionaire with hundreds of millions of fans was suddenly filled with bitterness: “You know”, he said, “that poor kid, he never even got to kick the football.” And it wasn't clear whether he was talking about Charlie Brown, or himself.