"The more you learn, the more you realize you're blessed," he said. "As people, we need to be humble. As people in Newport Beach, we need to be more humble than anybody else. We have so much stuff."
The Irvine resident, who will turn 59 years old on Dec. 22, was raised with four sisters, three brothers and a cousin. He left home when he was 14. He went to various high schools around the Los Angeles area, before settling in at John Muir High in Pasadena, where he lived with his uncle.
"When I say I haven't lived at home since I was 14 and a half, it sounds pretty weird," Sumner said. "But in those days, it wasn't that uncommon. In our old neighborhood, if you saw a 16-year-old girl pregnant, it wasn't a big deal. That was pretty normal. It was like, 'Why did she wait until 16?'"
Sumner said he was in about 100 fights a year during his teenage years. He has been stabbed, and he has also been shot.
"My whole family was in gangs," he said. "Sometimes people don't believe it; there's really no way to explain it. It wasn't good, but it wasn't like I was the only one."
But his interest in sports and especially running, encouraged by his uncle, provided a spark. He attended his first track meet at Mt. San Antonio College in 1960.
Sumner would later attend the college in 1967, and was a member of one of just two Mounties state-champion cross country teams.
Now, the man of many hats is busy. He is answering phone calls about the OC Marathon, now in its third year. Sumner expects over 12,000 runners and 40,000 spectators for the 26.2-mile course, which runs through parts of Newport Beach, Irvine and Tustin before ending near the Irvine Spectrum.
The marathon, which benefits 10 children's charities, has been a great success. And there's more evidence of Sumner's influence everywhere one looks.