That was until his fellow Royal New Zealand Air Force ground-crew colleagues explained to him that the old baked bean tins had been scattered around the tents so they could be warned of Japanese soldiers approaching their campsite at night from the dense jungle nearby - a sobering thought for the newcomer.
"We had no idea what we were coming into," he said.
The RNZAF squadrons began operating from the airfield from January 1, 1944, and just a couple of months before Mr Gray arrived on the island, the Japanese shelled the airfield and forced the squadrons to take off to avoid damage.
"The Japanese weren't that far away in the jungle.
"Luckily, we never heard any of those cans rattling in the night."
Like many returned servicemen, the 85-year-old is uncomfortable with sharing much of his wartime experience, and the insight into night life on the island was as much as he wanted to share.
"My war was a comfortable war, compared to what others had to put up with," Mr Gray said.
"I was just one of many people who did their little bit to chip away at the enemy."
He was happy to reminisce quietly about these experiences while selling New Zealand-made Anzac poppies at the Mitre 10 Mega in South Dunedin on Thursday afternoon.
Mr Gray said selling poppies was his way of showing his gratitude for the support the Returned and Services' Association gives.
Money raised from the poppy sales is used to support war veterans such as Mr Gray.
Nine years ago, he had a heart bypass, and during his recovery he suffered a major stroke.
"I've been extremely lucky. I've led a charmed life. I don't know why.
"All I can say is that I've been well looked after."
