LEIGH SALES, PRESENTER: Now to the next instalment in our series of Australians offering advice to their younger selves.

Catherine McGregor has had an eclectic career including the military, politics and cricket, and she is one of Australia's highest profile transgender advocates.

CATHERIN MCGREGOR, TRANSGENDER ADVOCATE: I'm a great role model about what not to do, basically, and that is squander talent, take ages to actually be honest with myself and the world about who I was.

(Video montage of Catherine MacGregor's life, starting with her in her military uniform)

MONIQUE SCHAFTER, REPORTER: Catherine McGregor was Australia's highest ranked transgender military officer.

In 2012 she was awarded the Order of Australia for her service to the Australian Army.

And in 2015 was named Queenslander of the Year.

McGregor has worked as an advisor for both the Labor and Liberal Party.

She's a cricket writer and player - and she was also a student once.

(Photo of Catherine McGregor as a young person before coming out as trans)

CATHERIN MCGREGOR: I had a loving family, a very secure home environment. I excelled at sport and a pretty good scholar as well.

So in a sense, with nostalgia, I feel my life was quite uncomplicated and relatively happy.

Of course, I always carried conflict about my gender and periodically worried about that.

I secretly would have been delighted if I'd known that it would end happily with me becoming a transwoman.

But I couldn't imagine- it was beyond my imagining.

At that age and in the country that it was in that era, in the circumstances I found myself, it was just too bewildering to behold.

It was something other people got to do and I couldn't.

I had two really burning ambitions at that age.

First was to go to the Royal Military College at Duntroon. I knew from a very young age that I wanted to do that, I wanted to be an army officer.

I have vague memories of my grandfather, but he was an AIF officer in the First World War; and my dad had fought in the Kokoda campaign and he was fiercely proud of his time as a soldier.

(Photo of Catherine's father in uniform)

He died very young and I think there was some unconscious part of me that wanted to connect with my dad, that wanted to get his approval.

And the Army was the only career I ever talked about.

(Black and white picture of Catherine as a child with a cricket bat)

I had an ambition in cricket as well. I'd been identified as a pretty talented young player.

I played some grade in Brisbane and then I had a couple of seasons in England as a young person.

But my life really unravelled while I was on the road, and I had a drinking and a drug problem and I never really achieved what I think might have been possible in cricket..

And it's one of my great regrets. I squandered my talent.

But that's life.

What I think I have come to appreciate with the elapse of time - and I'm at an age now where I've buried friends and loved ones, and far too many of them - so it tells me that life is precious and life is fleeting.

What I do know, after turning 62, is that you can generally reinvent yourself.

You can get through failure. You can overcome failure. You can get a lot of fresh starts.

So I love writing about cricket, I love talking about cricket and I love playing crick.

I'm still playing.

(Contemporary photo of Catherine in cricket whites)

There were moments when the stillness that I could experience playing cricket was just transcendental - complete congruity in my body, harmony with the external environment.

And I still love it and I think I'll go to my grave loving it.

MONIQUE SCHAFTER: What do you consider your greatest achievement?

CATHERIN MCGREGOR: There are two things.

One, I think I loved without reservation and with great depth, I was a good husband.

I was blessed to meet a person I think was destined to be my soulmate.

I still love her. I've never got over her.

Meeting and loving the love of my life was a great thing.

I will never get over her. I don't want to get over her.

I met the person I was meant to be with, and we're not together anymore - but that area of my life I'm content with.

I don't seek that level of intimacy with anyone else.

Just becoming the person I really think I was meant to be and feel deeply I'm meant to be was an achievement of sorts, because it required...

I went through an ordeal, I went through a nightmare

I walked through an arid desert in pain, distress and confusion before I gave myself permission to bring the real me into full and vibrant expression.

Your heart knows what your mind doesn't.

And life's lived forward but understood backwards.

(Photo of Catherine now in a blue jumper at a cricket ground)

So from my perception now, I would just say to any young people that I made every mistake possible -quite often by denying what I already knew in my heart, and so listen to your heart and trust your inner compass.

That's one thing I think at least I can say is, chaotic and unmanageable as my life has been at times, I'll at least die knowing I didn't have any runs left in the shed.