NEW YORK (Reuters) – You have to be pretty tough to make it as a four-star general in the U.S. military. So it makes sense that some top military commanders would get their starts working in rigorous first jobs.

For the latest in Reuters’ “First Jobs” series, we talked to a few retired generals about the life lessons they learned early on.

Martin Dempsey

Four-star general, Army; former chairman, Joint Chiefs of Staff

First job: Busboy

When I turned 16 back in 1968, I worked in a little diner in Greenwood Lake, New York. My parents were both blue-collar workers – my dad was a warehouseman, my mother was a cabinetmaker – and they wanted to instill that work ethic in me, so I started looking around and got a job as a busboy.

This was in the days before high-powered dishwashers, so the dishwasher was me and a sink. It was messy and hot work, and there was no AC (air conditioning) in the summer, so you can imagine what the kitchen environment was like.

I think minimum wage was around $2 an hour. My mom and dad paid for tuition at a Catholic high school, but anything other than that was beyond their means. So if I wanted to buy lunch in the cafeteria, or save for Christmas gifts, or take out my new girlfriend – who later became my wife – that was all on me.

Colin Powell

Four-star general, Army; former secretary of state, chairman of the Joint Chiefs of Staff and national security adviser

First job: Furniture store

I grew up in the Bronx in an area called Fort Apache, which I guess was a pretty bad neighborhood, but I didn’t know any better.

When I was around 14, my mom sent me to the post office, and I was walking along Westchester Avenue. There was a gentleman out front with long white hair, and he said in his thick Yiddish accent, “Hey kid, do you want some work?” I said, “Sure.” And I helped him unload a truck full of kids’ furniture like cribs and baby carriages. It was heavy work, but I was a pretty strong kid.

I ended up working there for years: Scrubbing floors, putting toys and furniture together. I was what in Yiddish they called a “schlepper.” In fact I picked up quite a bit of Yiddish from my boss, Mr. Sickser.

I made 50 cents an hour, and my first big purchase was a phonograph machine, with a little lid that opened and played 78- and 45-rpm records. I bought a lot of calypso and Johnny Mathis, whatever was popular in the fifties. My father was pretty unhappy with that purchase, because he was a hardworking immigrant and thought I should have saved it.

One evening, Mr. Sickser came up to me and said, “Collie, you’re a good worker, but I want you to understand, you can do more with your life. Finish your schooling, and find what’s right for you.” It touched me so much, that he cared enough to say that. I never forgot it.

Janet Wolfenbarger

Four-star general, Air Force; former commander, Air Force Materiel Command

First job: Cutting apricots

I grew up in the small town of Hollister, California, surrounded by orchards and produce fields. When my dad served in Vietnam, back when I was 11 or 12, my sister and I decided we wanted to earn some money. We got jobs cutting apricots – using a paring knife, slicing around the pit, dividing the fruit in two, and laying it on pallets to dry in the sun.

Most of our fellow workers were Hispanic, who didn’t speak any English, but they were so skilled at it. These women had been doing it for years. I learned a couple of important lessons from them: first, a strong work ethic. These women didn’t take breaks, and worked in the hot sun all day, and that money was so important to their families. Second, the power of teamwork. I remember one day, after I had been working on my single pallet for hours, a woman came over without saying a word and helped me finish, just so I could get paid for the day.

After five weeks, I made a grand total of $32 that summer. It was the first and hardest-earned wages of my life. I treasured that money, and put it in the bank. To me, it was a very big deal.

Charles Jacoby Jr.

Four-star general, Army; former commander, North American Aerospace Defense Command (NORAD) and Northern Command

First job: Salt mines

My dad was a mining engineer who worked at a Detroit-area salt mine. When I got to high school, he said “OK, now is the time to really learn how to work.” So I ended up working on a drill rig for two summers as a roughneck in Watkins Glen, New York.

It was unbelievably hard work. We fixed broken wells, or fished tools out of holes, or capped old wells – 12 hours a day, seven days a week. It was pretty demanding stuff, but I knew I couldn’t let my dad down.

By the end of the day, you were a mess. But learning how to get through a blue-collar day like that made you very proud, and very respectful of other men who are able to do that. It was a fundamental experience for me. Slinging pipe around, working with heavy equipment: It was very much like a day in the U.S. Army, minus somebody shooting at you.

It was also a pretty dangerous place, with chains falling out of derricks and pipes breaking loose. It was the first time I saw people really get hurt. It made me realize safety is not just a buzzword. Just like in the Army: Getting your guys out safely is part of the mission.