At age 10, he started working in a movie theater, covering the exit doors for 10 cents a night. By 12, he rented out rowboats and sold fishing bait off the pier at Beach 91st Street in Rockaway Beach.
A few years later, Coyle tricked his way into the ranks of the Navy during World War II, his family said.
He went on to work his way up in the insurance business and founded an independent agency specializing in employee benefits that's been operating for more than 40 years.
Coyle, of Rockville Centre, died March 8 surrounded by friends and family at his daughter's home in Manhasset after a brief battle with brain cancer. He was 84.
He was remembered by his family as a gregarious, resourceful man with a keen sense of humor and strong work ethic. He ran his first New York City Marathon at the age of 50, family members said.
Breaking the rules, he joined the Navy in 1944 at age 15, said daughter Deborah Coyle Benjamin, 57, of Manhasset.
She chuckled when she recalled how her father fooled the enlistment office: He used his deceased older brother Joseph's identity.
"I actually have his two dog tags -- one assigned to Joseph, and one assigned to Kenneth Patrick," she said.
Coyle was never shipped overseas, and when the war ended, Coyle Benjamin said her father assumed he was going home.
When he was told he'd have to stay in the military for up to five years, he admitted his deceit to his captain and was dishonorably discharged, his daughter said. He was, however, allowed to serve again during the Korean War, she said.
"He was very interested in the world and making a new challenge for himself," said another daughter, Denise Regina DeVita, 56, of Laurel Hollow.
With the help of the GI Bill, Coyle graduated from New York University. Prior to starting the Wheatley Agency in 1972 with partner Howard Trieber, Coyle was a manager at Connecticut General, now known as Cigna, the health insurance company.
Coyle was diagnosed with glioblastoma, an aggressive form of brain cancer, on Feb. 7.
In addition to his daughters, he is survived by his wife of 58 years, Gladys, 83; a son, Kenneth P. Coyle, Jr.; and three grandchildren.
CLARIFICATION: Kenneth Coyle joined the military at age 15 using his deceased older brother's name and was initially dishonorably discharged from the Navy due to his youth. But he was later honorably discharged on July 5, 1946. He received two medals for his military service. He rejoined the Navy later in 1946 using his own identity and served until he was honorably discharged on July 5, 1954. Family members misstated his military service in an obituary March 18.