‘‘I broke a tit,’’ she reveals in the first chapter, entitled ‘‘Vicodin, Valium and Veuve Clicquot’’. What follows is a witty, irreverent and self-effacing account of a dancing accident just before last Christmas in a Manhattan jive club that caused her saline-filled right breast implant to rupture.

The ‘‘aesthetic emergency’’ required surgery and Stephenson decided on an overhaul as well as a new implant.  She opted for a tummy tuck and the removal of her double chin and under-eye bags. 

‘‘One of the ugliest things about me,’’ writes the 62-year-old, ‘‘is my refusal to age gracefully ... I’m as vain as vain can be and would totally sell my soul to the devil to be a babe forever. Thank God for Botox, lipo and the surgeon’s knife.’’

Stephenson’s matter-of-factness about her cosmetic surgery – she also reveals she first had breast implants at 21 and has had a few rounds of liposuction – is refreshing and very un-Australian. 

‘‘I’ve lived in Los Angeles,’’ she says from her harbourside hotel room where she is ensconced during the Sydney leg of her national book tour. 

‘‘People don’t think anything of it. It’s like going to the dentist, people talk about it all the time. They talk about who’s getting what done, and all kinds of procedures. Everyone’s constantly tweaking. You don’t think twice about it,’’ she chuckles.

‘‘But as you age more, you realise some women think you haven’t had anything done. My stepdaughter, Cara, hit the nail on the head when she said, ‘It’s much more sisterly to ’fess up and tell people. You don’t want them to think that you haven’t had anything done and you’re this sort of medical anomaly’. 

‘‘I feel very generous towards those women who pretend they haven’t had anything done; there are men in their lives who apply pressure, there’s careers. They do what they think they have to do.

‘‘I also think that people should do whatever makes them feel better and some people feel better just being themselves and not bothering about it. The only thing that needs to be said is that you can’t come out strongly in favour of pushing back time surgically or any other way without remarking on the risks involved and there are risks. It won’t necessarily turn out the way you want it to, and it won’t necessarily make you feel better about yourself and it can be dangerous.’’

Stephenson, whose professionally honed comedic skill has been an effective defence mechanism throughout her life, can also see the link between her rush to fend off the effects of ageing and her fear of rejection – a common thread throughout The Varnished Untruth: My Story. 

She grappled with her tendency to make light of events and experiences when finally sitting down to write the book after struggling with the traditional format of an autobiography. Even after penning  Billy, the best-selling biography of her husband, Scottish comedian Billy Connolly, Stephenson did not know how to address the complexity of her life.

‘‘I could have written a different kind of book and I wanted to hide behind my ability to be humorous on the page,’’ she says. 

‘‘I could have carefully constructed my story because that’s what people in the public eye tend to do. And, in fact, everybody does that; creates an official story of their life that leaves out the awkward bits, the shameful bits, the bits that might make us seem less appealing, more ugly.

‘‘But then I thought, well,’’ she pauses and sighs, ‘‘it wasn’t so much that I had a choice, I just really felt bound to test waters and allow people to see the ugly side of me.

‘‘It’s in line with my tendency to take risks, my sense that it’s a good thing, it’s life-affirming.’’

Stephenson, who moved on from comedy to become Dr Pamela Stephenson-Connolly: clinical psychologist, began to question herself and this resulted in the unusual structure of The Varnished Untruth, which is essentially a lengthy therapy session divided into thematic rather than chronological chapters.

‘‘I didn’t come up with a structure until very late in the process,’’ she says. 

‘‘It just wasn’t working and I was very close to cancelling the book. I didn’t think I could do it, I didn’t really want to tell the story, and it was coming across as so raw.

‘‘I thought if I write it with hindsight and knowledge, people will think it’s boring. I had to be truthful to different parts of myself and it wasn’t until quite late that I came up with this idea of having a session with myself, a conversation with myself. Once I got that idea, it seemed to flow much better.

‘‘This particular voice is the one that began to write this book and would not be ignored and was only palatable because I was able to mitigate it with the therapist side of me.’’

Stephenson explores confronting events in The Varnished Untruth. She writes of the depression she experienced as a teenager, of losing her virginity while at high school to a 35-year-old heroin junkie – ‘‘A horrible, painful experience, out of which I got nothing but glandular fever and gonorrhea’’ – and her despair at being kicked out of home and placed in a Catholic hostel by her conservative, academic parents after they found out about her post-coital health problems.

They struggled to understand their creative, talented, wilful daughter, who was making a habit of sneaking out from her family’s suburban home at night and hanging out in Kings Cross (she ended up bar tending in nightclubs there and later became involved in a violent, abusive relationship). Her mother was ‘‘cold and judgmental, and her smile always seemed forced’’ and neither parent showed Stephenson or her two sisters any physical affection.

Being accepted into the prestigious National Institute of Dramatic Art saved Stephenson and launched her acting career in 1970. She played Cordelia in Edward Bond’s Lear, Solvieg in Peer Gynt and, when the Sydney Opera House opened, starred in two plays in the launch season at the Drama Theatre – Queen Isabel in Shakespeare’s Richard III, and Polly Peachum in Jim Sharman’s production of Brecht’s The Threepenny Opera. Stephenson was in demand for TV, film and theatre roles and her busy career provided her with the means to travel overseas. She packed her bags and travelled to London via Asia and Europe, including stop-offs in Japan and India. Stephenson had lived in London for a year in primary school while her parents took up sabbatical posts at the Chester Beatty Research Institute and that experience, during which she attended the Arts Educational Trust, exposed her to acting and unleashed ‘‘a full-fledged performing monster’’.

It was fitting that it was in London where she arrived as an adult, a ‘‘kind of female Crocodile Dundee’’, with £20  in her pocket that she would achieve stardom in the 1980s with her role in the irreverent satirical sketch show Not the Nine O’Clock News alongside Rowan Atkinson, Mel Smith and Griff Rhys Jones. She was the sexy blonde with a knack for hilarious impersonations of Madonna, Margaret Thatcher, Billy Idol, Kate Bush and Olivia Newton-John.

While she was whooping it up on screen, off camera she was ‘‘very thin and edgy’’, a chain-smoking Buddhist who abstained from salt, sugar and fat, and also meditated for long periods to manage her performance anxiety. 

‘‘I wasn’t exactly fun to be around,’’ she remembers. But it was during that time she met Connolly when he made a guest appearance on the show. There was an instant attraction. 

‘‘He was thrilling; a savage gypsy lover with a voice like gravel and honey,’’ she writes.

Both Stephenson and Connolly were married at the time, and there was also the issue of the Scottish comedian’s alcoholism. After escaping to Bali in a futile attempt to forget Connolly and her failed short marriage to British actor Nicholas Ball, Stephenson returned to the UK and her ‘‘gypsy lover’’. Connolly got sober and the couple became a paparazzi target. A decade after their first meeting, they married in Fiji in 1989 in the presence of Connolly’s two children, Cara and Jamie, as well as the couple’s three young daughters, Amy, Daisy and Scarlett.

Fast forward 23 years and the couple has joined the small and exclusive club of celebrities who have long-lasting marriages. Both Stephenson and Connolly live very full lives and have vastly different interests. 

‘‘We know that relationships work when people are their own individual selves and they’re able to be who they are and also be together,’’ she says. 

‘‘If you always know what the other person is thinking all the time, well that can get really boring. He’s off with his trikes and his motorbikes and movies, and I’ve got my dancing, writing and scuba diving.

‘‘We’ve always travelled independently. We spend chucks of time apart; right now I’m on the book tour and he’s at home in New York.’’

Stephenson, who writes a weekly sex column for Guardian readers seeking advice about sexless marriages, cross-dressing boyfriends and how to achieve orgasm, has always been an adrenaline junkie and her autobiography includes her various adventures in far-flung places, including Borneo and Papua New Guinea. Though one of the biggest risks she has taken recently was closer to home: her decision to perform in the popular British TV show Strictly Come Dancing, which has a similar format to Dancing With The Stars here.

The former child ballerina made the 2010 final and found the experience transformative. ‘‘It was fantastic to survive in it that long and a lot of it was public vote,’’ she says. 

‘‘I have always loved dancing and I still do it any chance I get.’’

The long-time devotee of the Argentine tango has now embraced the sexy Brazilian style of dance called lambazouk, which evolved from the lambada. 

‘‘I’ve just been in New Zealand before arriving in Australia and the first night in Auckland I went online and found there was a zouk party and I went along by myself.

‘‘I’ve even organised some zouk flash mobs at my book launches to surprise the audience,’’ she says laughing (see YouTube for dodgy video of the Perth event). The delight in her voice is obvious when she talks about dancing.

‘‘It’s wonderful and I’m drawn to the zouk because it’s Brazilian. They’re so comfortable with their bodies and I’ve found Brazilian men to be accepting of women of all ages and all sizes. It’s a fantastic feeling being able to express yourself without fear of judgment.’’

One of the most significant realisations for Stephenson while writing The Varnished Untruth was that she suffered from destructive body dysmorphia for the best part of two decades, if not longer. 

Even at the height of her success while appearing in Not The Nine O’Clock News, she saw herself as a ‘‘toothy, short-waisted, pear-shaped munchkin with an unfortunate facial profile’’.

‘‘Shocking, isn’t it?’’ she sighs. 

‘‘Even I can look at that and go, that’s terrible. Why couldn’t I have just relaxed and been happy to look the way I did? But that’s what body image problems do. 

‘‘I looked in the mirror and I saw something very different. When I  saw photos in magazines, I’d say, ‘Well, that’s me after an hour in the make-up chair’.

‘‘What we’re talking about now is ubiquitous for many women and the pressure is on us to look amazing. Most women are fabulously flawed in one way or another, and wouldn’t it be nice if we weren’t ashamed of that?’’

What has she taken away from her lengthy conversation with herself?

 ‘‘The most important thing is to come into the world with parents who help you to feel safe – doesn’t even have to be your parents, you just need one person in the world who makes you feel secure, loved and appreciated for who you truly are.

‘‘We’re all multifaceted and we can all venture into dangerous terrain, but it is important there’s somebody who’s watching over you.’’

The Varnished Untruth is published by Simon & Schuster.