I have a long-held secret, but it is time to reveal it and give up on my dreams. Every set of birthday cake candles I blew out as a child, every wishbone snapped at a chicken roast dinner, I always wished for the same thing: that one day I would play in the NBA.

The closest I came to realising this wish was meeting Steve Nash, the eight-time NBA all-star. I was a gawky kid and what I remember most about the encounter is that he had spectacular, sharp sideburns that went right down to his jawline. I hoped but failed to emulate his unexpected triumphs in the greatest of basketball arenas. I did, however, manage to hold on to another dream and see it through to completion: winning a gold medal at the Olympics.

Winning at the Olympics requires an all-consuming level of dedication. In my experience as a rower with the GB men’s eight team, the prologue of arduous and repetitive training extends for many years before the punishing routine and harsh selection battles all culminates in one single event, the pinnacle of sport, the Olympic Games. This event is likely to define an athlete’s career, and the result will be internalised by that athlete for the rest of their life.

When you head off to the Olympics the stakes are ridiculously high. The start line is a punishing and exquisite place. I love the buzz. I know everyone in the warm-up area deserves to be there. Each athlete has pushed themselves to excellence, hurting themselves over and over again in order to represent their country. That is an inspiration in itself.

There is a brilliant intensity of emotion bubbling under the surface of the focused, concentrated and hard exterior of an athlete ready to perform. It is a raw experience that taps into the primal – the fight or flight response. The strange and potent combination of fear, rage and readiness that circulated throughout my body before the start buzzer in Rio is a feeling I will never forget. It is an addictive sensation: bold and blinding, beautiful and horrible in equal measure. If I could go again tomorrow I would, but it takes at least four years and a considerable chunk of your soul to earn that spot on the start line.

The race itself flew by in a blur of perfection. I knew my crew were capable of big things but we had to do it on the day, when it really mattered. I share a common trait among the team: an obsessive eye for improvement. This unflinching commitment to ceaselessly perfect my rowing is compatible with the high-performance programme we follow. Every detail is torn apart and every performance analysed to yield the next speed gain.

This perhaps explains the strangeness I felt after the Olympic final. There was very little I would change about how we executed that race. The smallest of details that I did pick up on did not matter. We had won the big one. The one that mattered. The one that I had strived for over so many years. In an instance that machine-like process had stopped. I no longer needed to analyse or to perfect. The end product had been reached. The regimented and planned timetable of training no longer existed. I was free.

It is akin to line-dancing off a cliff. For nearly a decade coaches had mapped out every stage of my training. Every session was programmed, every day accounted for, and then abruptly the race was over, and it all stopped. It is disorienting: an alien sense of freedom, tinged with loss.

On crossing the finish line the sensation was unexpected. I was aware of what had happened but I felt somehow detached. I knew everyone was celebrating and going crazy, but by contrast I was still. I don’t understand why this was the case. It was as if my body were empty, or completely drained, and it felt as if I watched all this from outside of my body. I could hardly feel anything. On the landing stage I felt like a ghost. The effort was total, and I was exhausted. We had brought everything we had to those five minutes and 29 seconds of racing. I felt sick and disoriented. I think I was so overwhelmed by the experience I had no energy left to process what was happening. At some point someone sat me down and placed an ice pack on the back of my head/neck. The ice was bliss. It returned the world to focus. I knew this feeling, as surreal as it was, trumped the devastation of four years ago. In London 2012, we had led the Olympic final but were rowed down by two crews, and the bronze medal felt a very bitter type of bittersweet.

Tom Ransley top row, second from left: ‘In some ways to be awarded the gold medal felt as surreal as if I found myself sitting beside Goldilocks eating porridge with the three bears.’ Photograph: Mike Egerton/PA

This time, standing on the podium I pondered a truly surreal experience. It had all the trappings of an Olympic prize-giving. I was being awarded the Olympic gold medal. I could hardly take it all in. At one point in the proceedings a brief and casual thought popped into my head: this is all a construct, purpose-built for effect. The Olympic prize-giving is a piece of televised theatre. Despite an absolute belief that we could win, our plans and visualisations never extended beyond the finish line. In some ways being awarded the gold medal felt as surreal as if I found myself sitting beside Goldilocks eating porridge with the three bears.

We dived headfirst into a whirlwind of parties. The city was alive with carnival-like celebrations. Unfortunately my energy levels waned with alarming speed. After a week I began to crave some normality. I ended the party-marathon the morning after the closing ceremony with several sleepless, singing Brits: there were four gold medallists across two different sports, shooting vodka from a paper cup at 7am in the Olympic food hall. This was not normal.

By the time I boarded the flight home I felt as if I were nearing the end of an endurance event or some kind of sleep deprivation experiment. I was fast approaching breaking point where the next selfie, photo-op, or glass of champagne might be terminal. Apologies to the lovely BA staff who kindly served me a glass of champagne – I just couldn’t face it. After no teammates accepted the offer I had to surreptitiously pour it down the sink at 30,000ft. For the first few hours of the flight I rapidly flitted in and out of strange dreams. I kept lurching back into consciousness, puncturing the snatched and restless sleep. In the end I opted for a Baileys. It did the trick. I was asleep in no time.

The next thing I knew, I stood bleary-eyed, in front of the world’s media. I felt decidedly the worse for wear and no doubt I didn’t look particularly fresh. I would like to apologise to all the fans that crowded every section of the airport, from runway to bag carousel to car park. It was incredible to have so much support, and I am deeply sorry for my detached look. I was so desperate to get home that I might have been tempted to trade my newly acquired gold medal to be teleported to my bed.

I slept for many hours when I got home. I felt quite rough at first but am starting to feel a bit more human now. I have spent most of the last 10 years preparing for major sports events, so the time following an Olympics can feel a bit empty: I felt a similar void after London. I like to have goals and targets to work towards and if I am not being productive then I can get frustrated, so losing the focus of winning the Olympics is a giant gap to fill. However, I enjoy visiting schools and other organisations to help inspire other people and share the positive values of sport.

From within my chaotic and surreal memories of Rio grows a quiet satisfaction of a job well done; the pleasing knowledge that our crew executed the race in a manner we knew we were capable of, and that it was good enough to win the Olympic gold.