I enlisted in the army just after high school, and served in the Combat Engineers. My dad has gifted me a Camillus Boy scout knife when I was 12, and had joined a local Boy Scout troop. I had carried that knife until I enlisted, and left it home because I had been informed that things sometimes disappeared in barracks and the knife had developed some sentimental value to me.
When I arrived at Engineer school at Fr. Leonard Wood, Missouri after boot camp, we were issued a few things right off. Steel toe safety boots, and a Camillus model 1760. This was an all steel scout knife, often called the demo knife. This a bomb proof version of the Boy Scout knife and I carried that knife for about half of my 10 years I was in the army. It was only replaced by a Victorinox pioneer when I was serving a tour in Germany, and I was lured into a knife shop by a giant moving Swiss Army knife in the window. That was the start of my love of SAK's.
I carried a Buck 301 stockman for a while, but the SAK was my main knife. It did everything I needed from a pocket knife, and then some. I had been used to having a few tools on my knife from my boy scout days, and that never faded. Even with a tour in Vietnam with the 39th Combat Engineers, I didn't really need more life than that. Our squad tool box held two hatchets and two Ontario machetes, so if more blade was needed, we just used a machete. There was also a pointy thing that went on our M16's, called a bayonet. But the 'demo' knife was enough for most things.
When a construction accident smashed up my right foot and ankle, and they gave me a medical discharge and a cane, my Victorinox pioneer was in my pocket when I limped out of Walter Reed Army Hospital in Washington D.C.. The Camillus demo knife was in my duffle bag. My youngest son has it today.
Over the next 50 years, not much changed. I still carry a SAK of some sort most the time, and its enough. Being knife nut means a lot of knives have come and gone. Mostly gone, when I figured our that I didn't really need them.