Eight actors have played the title role on Doctor Who, Britain’s decades-old time-travel series, yet the fourth, Tom Baker, is still the most famous and beloved. Just as the most Trek-ignorant tv viewer knows who Mr. Spock is, so does Baker’s unforgettable appearance–thick brown curls, floppy hat, long coat, and enormous striped scarf–stir a vague recollection, even among the jaded and uninitiated. Many factors contributed to Baker’s popularity (besides the costume), including excellent writing, strong supporting acting, and the fact that he played the part so damn long (seven years, a generation in television terms). But the true magic of the Fourth Doctor was Baker’s own. No-one captured the essential alien-ness of the character as he did, or suggested so much of the strange depths to be found in this 700-year-old Time Lord’s brain.

Baker inhabited a scene with a physical presence completely unlike that of anyone else. As Jeremy Brett would later do with Sherlock Holmes, he depicted genius as a kind of impairment, as if the Doctor’s brain ran too hot and too fast, its energy spilling over and sparking the tantrums, fusillades of sarcasm, and stony meditativeness that all served to distance him from those around him. Many of Baker’s fans (including this one) have suspected that weirdness on such a baroque scale could not be merely the product of the actor’s craft. Surely something deep within the man himself informed all those strange jokes and abrupt silences?

You don’t know the half of it. Baker’s autobiography, entitled Who on Earth Is Tom Baker?, is an eye-watering litany of suffering, embarrassment, bad decisions, and unbearable self-loathing; in fact, of all the biographies I have read, auto- or otherwise, only Charlie Chaplin’s begins in greater misery or maintains such a fever pitch of self-doubt and unhappiness. Yet, whereas Chaplin saw his life as tragedy (with a happy ending tacked on), Baker sees his for the picaresque that it is. The book is packed with witty asides—he describes his father noisily sipping tea as sounding “like pebbles being shoveled into a zinc wheelbarrow”—and steeped in a lacerating humor that its author turns on others as freely as he turns it on himself.

The hilarity starts in an Irish neighborhood of war-torn Liverpool, where Tom Baker was born and where, as a boy, he prayed that his mother would be killed by a falling bomb on her way home from work, so that, like Liverpool’s other war orphans, he might be showered with gifts and toys from America. The supreme being denied him this favor, yet this didn’t stop Baker from deciding that the religious life was for him. There was little else open to this gangly, repressed misfit: “The main thrust of a Catholic education all those years ago was self-loathing. The more you despised yourself the better you were … [I had a] feeling of self-loathing and a desire to be a slave to someone, anyone, as long as he knew what life was about and didn’t mind if you were thick.” At the age of 15, after years of dutiful altar boy service and general religious brown-nosery, he entered a monastery.

There were no beatings, no fire-and-brimstone sermonizing: just long hours of work, prayer, meditation, and endless, agonizing solitude. The novices were forbidden to make friendships, to laugh or converse idly, and the rule of modesty prevented them from so much as raising their eyes to each other; only once did Baker succeed in looking one of his fellow novices in the face. After nearly six years, half-mad with loneliness and filled with a gnawing itch to break all ten commandments (“Especially I had the urge to kill, steal and bear false witness”), he left the order.

Years of living in such self-abnegating solitude gave Baker an awkwardness around people which he never entirely lost. He completed his compulsory two-year stint in the Army without having made a single friend, and entered into a short-lived, disastrous marriage with a wealthy heiress with whom he had nothing in common and whose family despised him. Fortunately there was one avenue left to him. His performance in an Army theatrical led a fellow actor to offer encouragement: “‘[Y]ou’re terrible at the moment, absolutely bloody terrible, but there’s something in you that might make it work if you can find anyone to give you a chance.” Many did give him a chance, including Laurence Olivier, who took him into the prestigious National Theater company, where Baker played small parts and understudied big ones. His successes were modest, like those of most struggling actors, and he was supplementing his income by laboring on building sites when the BBC invited him to audition for Doctor Who.

Baker’s years as The Doctor are presented as a confused whirlwind, one that turns the shy actor’s world upside-down. Baker led the program to its greatest popularity and, arguably, its creative peak as well; and the formerly withdrawn, nigh-unemployable actor became a hero to children and a lust object to their mothers, and loved every minute of it. To please his young fans he carried hundreds of giveaway pictures and buttons and stickers, signed autographs until he was paralyzed with cramp, and never allowed himself to be seen drinking, smoking, or swearing. To please the women he climbed into bed with them, spanked them or allowed himself to be spanked according to their preference, and even permitted one enthusiastic fan to wear his costume (minus the pants, one assumes) while they did the nasty (“I kept thinking I was shagging myself”). Years whizzed by in a blur–Baker’s recollection of these events is frustratingly haphazard–and his commitment to the role finally swallowed him up. Increasingly critical of scripts, directors, and the boring new characters he’d been saddled with, he left the show in 1981, confidently awaiting a flood of offers that never came.

There’s something elegiac about the rest of the book, and for that matter about the footnote that is Baker’s post-Doctor Who career. He spent much of the eighties in bars, drinking with cronies while his second wife waited for him to come home. The story gradually shifts to the present tense as Baker occupies an old schoolhouse with his new, third wife, where he is content to cut the lawn, tend to his gravesite (his headstone is already carved and set out for him, awaiting only the inscription of the final date), and deal with the occasional oddballs who seek him out. He settles into old age with the contentment of a man who knows how lucky he has been, and who is determined not to squander a relationship that might be the last stroke of good fortune life will deal him.

Though the book’s ending is as much of a downer as the beginning and middle, you feel grateful for that first stroke of luck that landed Baker his enduring, if esoteric, fame. Without the role of The Doctor, Baker’s reputation would carry no further than the few drinking buddies who still remember him; after all, hard-drinking, out-of-work actors are a dime a dozen. Men who have lived the sort of life described in this book, however, are a rare breed. Though he would be loathe to admit it—the rule of modesty rearing its head again, perhaps—Baker is a survivor, a man who, despite an upbringing that would crush many a lesser man’s soul, created a character famous throughout the world for its humor, energy, heroism, and unkillable vitality. Spend the few hours and get to know him.