Nudity. That was always my problem with spas. I didn’t know if it would be required, and if so, at what stage in the proceedings. Fear of the unknown, and of potentially embarrassing faux pas, kept me away. I felt no sense of loss because I didn’t know what I was missing.

Eighteen months ago, I finally took my first steps into this alien world, and I discovered that it wasn’t so daunting after all. Everything was tastefully done; modesty was subtly preserved. I became familiar with the customary vestments: the towels, the robes, the plastic sandals. And the paper thongs.

So while not exactly a spa veteran, when I descended the two flights of stairs from my sumptuous room in the Mandarin Oriental Hyde Park to the basement spa, I thought I knew what to expect.

It was seven o’clock on a Saturday morning, and I was the first booking of the day. In the reception area I was divested of my shoes and socks and slipped into a pair of slippers. I filled in the health questionnaire before being led down to changing rooms. So far, so familiar.

Downstairs there were separate spa facilities for men and women. I had been advised to check in well ahead of my treatment in order to spend some time relaxing. The receptionist showed me to my locker, which contained a towel and a robe. “Jaqueline will meet you in the relaxation area in 30 minutes,” she told me. “All you need to wear is the robe.”

“Nothing else?”

“Nothing.”

Left to my own devices, I filled the locker with my clothes and, just to be on the safe side, donned my red swimming trunks. I headed first to the Amethyst Crystal Steam Room. A scented fog enveloped me. Humidity invaded my lungs. I inhaled deeply. Clammy warmth percolated through me.

After several comfortable minutes in the steam, I moved to the Vitality Pool, immersing myself in its hot mineral waters. Eventually I toweled myself down and put on the robe. I hesitated to execute my final duty. But it had to be done. I removed my trunks.

In the relaxation room, I had my pick of the beds. Soft music played. The subdued lighting scrolled through subtle hues. I was just about to drift off to sleep when Jaqueline appeared and led me up a flight of stairs to the treatment room where I was booked in for two hours.

We began with a consultation. Still swathed in my robe, I sat on a chair with my feet in a bowl of warm water. Jaqueline asked how I wanted to feel after the session.

“Thoroughly relaxed,” I said.

“And what do you have planned for the rest of the day?” she asked.

“I’m going to have a walk round town. Visit a couple of museums.”

“So relaxation is not exactly what you’re looking for,” she chastised. “You’d be in no fit state to be active. What I recommend is a full facial, a body scrub and a hot stone massage. How does that sound?”

Still being unaccustomed to the range of spa treatments, it sounded incomprehensible. But I assented.

“Okay. Pop your robe over there and hop up onto the treatment table.”

This was it. Off went the robe. With as much dignity as I could muster, I clambered up onto the treatment table and lay down on my stomach.

“We’re starting with the facial, so you’ll need to lie on your back.” Jaqueline kept her gaze diplomatically averted as I completed the maneuver, then she draped a towel over me from neck to toe. Thus concealed, I was able to relax.

While the prospect of nudity had always put me off spas in the past, it wasn’t the only deterrent. There was also the issue of lying around doing nothing for a couple of hours. If boredom didn’t set in, sleep soon would. During my first-ever spa treatment, in Thailand, I comprehensively nodded off and was unconscious for all but the first few minutes of my session.

But lately I had begun to discover that lying around doing nothing can be pleasurable in itself. As Jaqueline massaged the various pressure points on my head, I regulated my breathing to the slow rhythm of the background music, and found myself enjoying the experience without guilt. Time stood still. The cares of the world receded. I would happily have remained there for the day.

Next came the salt scrub. Jaqueline folded the towel down to cover only my bare essentials, then set about the process of exfoliating my skin. With a scratchy brush, she swept away a lifetime’s accumulation of dead skin cells. Then she applied the scrub. The benefits of this procedure endured for several days — never had my skin felt so soft and smooth.

The treatments and “rituals” at the Mandarin Oriental Hyde Park draw on a global range of therapies and philosophies, incorporating Chinese, Ayurvedic, European, Balinese and Native American elements.

Much of my session was devoted to chakra balancing, which apparently restores “harmony and balance to the body’s energy system.” Generally I don’t have much patience with “chakras” and “energy systems,” but lying there stripped naked — both literally and metaphorically — I allowed the energizing body oil, the essential body polish, the pink hair and scalp mud, and the hot stone massage to work their mystifying magic.

Two hours flashed by. Jaqueline provided me with a hand-written product recommendation sheet (my skin, it seemed, was shockingly dry, and she urged me to adopt a regular exfoliation regime). Then she escorted me back to the relaxation room where, having not yet had breakfast, I made good use of the platter of fruit on the table.

Later that morning, still cocooned in the post-spa aura and wafting a scented trail, I headed out into London. An easy 30-minute stroll took me to the National Gallery, where I ambled among some of the world’s greatest works of art. There was no shame about nudity here. In shades of white and pink, expanses of flesh were shamelessly revealed. Passed down through the centuries, the truth was plain to see: Nakedness is our natural state.