One afternoon 32 years ago — at age 9 — I stood at the base of the Great Pyramid of Giza and discovered a new gauge for the size and age of things.

Until that moment, I thought I knew what big was. But this was big on a different scale. I had a concept of age. But now I found that adults were not quite as ancient as I had presumed.

I measured myself against one of the stones at the base. It was almost beyond comprehension that 2 million of these massive blocks were stacked above me. The ragged flank of the colossal structure sloped upwards. The sky itself appeared to be balanced on the pyramid’s pointed zenith.

The timeline was just as amazing. The pyramid had been built 4,500 years before. My entire lifetime barely registered against that history. Suddenly I acquired a shocking sense of my comparative place within the greater scheme of things: I was infinitesimally small and my life was just a flicker in time.

Approaching Giza three decades later, I expected to be moved by similarly profound insights. The memories of that first visit remained vivid, and I hoped to be uplifted and spiritually enriched by revisiting this significant milestone from my childhood.

Sadly, the main revelation of my return visit was that I had become a grumpy middle-aged man.

Although the pyramids and the sphinx were unchanged, everything around them had been transformed beyond recognition. In 1976, Giza lay 15 miles from downtown Cairo, separated by a stretch of pale desert. The city has tripled in size since then, and the outskirts now lap right up to the pyramid complex.

When I first came here, Egypt was recovering from the 1973 October War with Israel. There were few tourists in Cairo. When we drove out to the pyramids, our battered Peugeot taxi was the only vehicle there.

Going back, I was unavoidably absorbed by the current tourist hordes. I had joined a group of 30 people aboard one of the many coaches that shuttle back and forth from the city hotels. Through the windshield, I glimpsed the iconic, triangular silhouettes looming beyond the apartment blocks that lined the highway. My heart soared. Then the guide announced that we would stop first at a souvenir shop. “Forty minutes, please,” she said. My heart sank.

It was a souvenir shop of the tackiest sort. After a cursory glance at the stuffed toy camels and plastic sphinxes, I returned to the coach. An hour later, we were still there, waiting for the stragglers. It was a routine that would be repeated at every stop.

Next came lunch at a roadside restaurant close to the pyramids. I wolfed down the meal, eager to be on my way. But I had to wait for the others to haggle over their bills, followed by their protracted visits to the restrooms. Another hour went by — insignificant for a pyramid, but an age for me.

Finally we reached our goal and parked alongside dozens of other coaches. Hundreds of tourists swarmed like luminous ants around the base of the Great Pyramid. In a darkening mood, I slunk off around the corner where, with relief, I enjoyed a moment of solitude. But I was soon spotted by hawkers. One tried to sell me a set of postcards, another wanted me to take a ride on his camel.

The group trooped back to the bus and waited in stifling heat, flies buzzing around us. Two people were missing. It turned out that they had gone for a camel ride. At last they returned and we resumed, driving to a ridge for the classic view of the pyramid complex.

Several hundred tourists were there before us. I handed someone my camera, forced my way through the crowd, and sidled down the slope to pose for a photograph alone. Just as it was taken, a toothless Egyptian in traditional dress put his arm around me and demanded payment. Fortunately, I was able to show him digital proof that he hadn’t been in the frame.

Then it was on to the sphinx, and another battle through the masses to find a clear view. Everyone had the same idea: We were all vying to take pictures th at omitted the throng of fellow tourists. And thus the myth of a thousand travel brochures is perpetuated — the pyramids and sphinx always appear set in splendid isolation.

The following day, I attempted a guided tour through the extraordinary Egyptian Museum in central Cairo. The fabric of the place had not changed at all since my previous visit. I doubt it had even had a lick of paint since then. Priceless antiquities, including the famous golden mask of Tutankhamen, were displayed in oldfashioned glass cases.

The dense crowds were here as well. Polyglottal commentaries echoed in every gallery. By contrived accident, I became detached from my group and savored the freedom of exploring the museum at my own pace.

By now I was adjusting to the permanent crush and noise of Cairo, and I was less grumpy. In the mornings I savored the view of the sluggish Nile from my hotel room, then plunged headlong into the city. Every taxi journey was a chaotic maelstrom punctuated by blasting car horns.

In the old town souk, Khan el- Kalili, I roamed the maze of narrow alleys, worming my way through the jostle of people and mules and bicycles. I bartered and bantered and loved every minute.

During my time in Cairo, my view of the world shifted. It was a change of perception as radical as the one I had experienced as a 9-year-old facing the Great Pyramid.

I realized that my constant longing for solitude was a denial of reality. When the pyramids and sphinx were built, the total human population of the world was around 20 million. In 1976, the global population was 4.2 billion. Today it is 6.5 billion.

Market crowds, the Cairo traffic, the expanding suburbs and the jostling tourists are a measure of humanity’s success. Like it or not, we are all part of humanity.