Jimmy Hernandez went skydiving for his 100th birthday. The centenarian lives independently with his wife and still climbs onto the roof of his home to do maintenance.

At 100 years old, Jimmy Hernandez still drives a car and climbs on the roof of his home to do maintenance and repairs.

He lives independently with his 91-year-old wife, Dora, loves to dance and just fulfilled a big wish: The great-great-grandfather went skydiving for his milestone birthday on Aug. 29.

He was intrigued by the idea after watching the late President George H.W. Bush take the plunge in his 80s and 90s.

"It wasn't scary. I wanted to do this jump for some time," Hernandez, who lives in San Luis Obispo, California, tells TODAY.com.

"I knew if something happened, it would be the last (thing I did), but it came out pretty smooth."

Some of his loved ones were taken aback when they heard about his plans.

"I thought he was a little crazy," his granddaughter, Vickey Hernandez Farley, 51, tells TODAY.com.

After Hernandez jumped out of the plane for his tandem skydive, his son and grandson followed suit to make it a family affair.

The World War II veteran says it was his highest leap since he had to jump 18 feet down into a swimming pool to make it in the U.S. Navy as a young man. "It was pretty high for me, but this is a little different," he adds.

Hernandez, who is already thinking about skydiving next year for his 101st birthday, says he has some health problems, but generally feels well. He's never had cancer or heart disease.

Here are his simple tips for living a long, healthy life.

After serving aboard a destroyer tender in the Pacific during World War II, Hernandez was a carpenter all his life, starting at 22 and retiring at 91.

He worked this primary job, plus side jobs to support his 12 children, driven to keep the family going.

Hernandez credits "help from up above" and his work ethic for his longevity.

"I worked hard all my life -- very hard and many hours for my job," the centenarian says.

He still does occasional carpentry, plus the maintenance work around his mobile home, including getting underneath it or climbing onto the roof when needed.

People urge him to stay off the ladder, but he always gets the job done, "so I can't stay off the ladder. I do my own stuff," Hernandez points out.

It's important to eat right, move your body and have your mind clear, Hernandez says.

"You've got to live a clean life and don't abuse liquor or smoking or even food," he advises.

"You can't just sit and watch TV because you get fat. You've got to exercise... You can't just let yourself go."

Hernandez has always been healthy, in part because he's always been active and on the go, his granddaughter believes.

With five generations of the family alive, she's glad to be inheriting such great genes.

"I want to live a long life like my grandfather, for sure. But I want to be in his health if I'm going to be around that long," Vickey Hernandez Farley says.

Longevity runs in the family. Jimmy Hernandez's mother lived to be 90, and one of his aunts lived to 102 years old.

He's hoping to make skydiving an annual tradition. "If God keeps me here, I don't mind jumping every year," he says.

The centenarian has liked to dance since he was a teenager, and he danced at his 100th birthday party the family threw for him.

He cooks steaks, enjoys an occasional shot of tequila and likes sweets.

"Dessert, I've got to have that," Hernandez says. "We always have coffee and pie. I like peach pie and apple pie. A donut once in a while."

He's an optimist and has a positive outlook on life. "You've got to live positive. I think that's the only way to go," he says.

Born in Escalon, California, to parents who came to the U.S. from Mexico, Hernandez has been married to his second wife, Dora, for 57 years.

He's the father of nine girls and three boys. His large family also includes 34 grandchildren, 64 great-grandchildren and 24 great-great-grandchildren.

The family has a reunion every year, and his loved ones visit regularly.

"Love people. That's what my mom and dad taught us -- to love and hug each other," Hernandez says. "You've just got to enjoy life and trust everybody and respect (others)."