(CNN) -- Kimberly Brewer's most memorable Father's Day was the one when she realized how much she would miss him.
It was 2005, less than two months after retired naval corpsman Wallace J. Keyser had died unexpectedly of complications from pneumonia. Her heart sank while she watched Father's Day-themed commercials. She remembers walking through Barnes & Noble and seeing a World War II title that he would love and realizing there was no need to buy it.
"That is the most memorable Father's Day ever, to realize the impact of loss and yet cherish the gifts given by that very same devastation," said Brewer, who shared her story on CNN iReport. "I missed him that Father's Day and every day since, but count myself as oh so fortunate to have had such an amazing man in my life."
It's easy to write off Father's Day as yet another meaningless Hallmark holiday until you no longer have someone to send a card to. For those people, the day can be bittersweet, a reminder of the good times and all the times you'll never again share.
And for others, the day is an opportunity to celebrate all the ways dads make our lives better.
Brewer's father inspired her to join the Air Force and push on to become a captain select. She shares his love of cars, Nissans in particular, and recently bought her dream car, a loaded Maxima. Yet, she couldn't help but feel sad that she couldn't share it with him. A child of the Depression who lived through the Korean and Vietnam Wars and Hurricane Isabel, he taught her a lesson or two in resilience. After he retired from the Navy, he went to college on the GI Bill and became the first person in his family to get a degree.
Missing a dad on Father's Day can evoke the ache of loss, but some rely on happy memories to get through the day.
Carla Hurst-Chandler remembers when the family surprised her husband with the gift of a lifetime for Father's Day.
William Edward Chandler was smitten with an antique classic Guild Guitar that he'd spotted at their local music store in Greencastle, Indiana. Carla made a deal with the proprietor to make small payments on the $1,000 guitar with her sons so it would be theirs in time for Father's Day 1996.
For weeks, she stopped in and paid installments for the guitar, along with and her sons, ages 7, 8 and 9, who pitched in part of their weekly allowances, Hurst-Chandler said in an iReport.
Rod, the store owner, was in on the plot too, she said. When her husband stopped by to see his coveted guitar, Rod shook his head and told him it had been sold.
"That night was the hardest of all, when he came home and glumly remarked that it had sold," she said. "And the boys and I commiserated with him, knowing that it was sold all right ... to us."
When Father's Day arrived, they were up early as he slept in. When he came down for breakfast, he walked into the kitchen and found the guitar case open to reveal his dream guitar.
"The look on his face, the double-take, the happiness, was priceless!" she said. "The boys and I lost Bill to leukemia in 2010 and spent many wonderful Father's Days with him between these years. But this was his best Father's Day surprise ever."
Paul Olmstead's children imbue Father's Day with new meaning for him. But he still wishes his father were around to enjoy his three sons. Duane D. Olmstead was diagnosed with pancreatic cancer in 2001 and told he had six to 12 months to live, Paul Olmstead said in an iReport. He didn't want to try chemotherapy or radiation and decided to see what a raw, vegan diet would do for him.
He ended up living for five more years, during which his relationship with his family changed dramatically, Paul Olmstead said.
"We always had a good relationship, but not super close where we shared intimate things or I would ask for his advice. That changed fairly quickly after his diagnosis," he said. "It softened him a bit."
Paul Olmstead said he also learned from the experience. It strengthened his faith and prompted some changes to his diet: less sugar and processed foods, more fruits, vegetables and whole grains, though his family is not vegan.
The importance of hard work and family has also taken on a new meaning, he said.
"My dad left a legacy to me, my three siblings and our families that we should value our work or whatever we are doing. Don't just work hard; do quality work. Be able to look at what you've done and be proud of it because you know you gave it your best effort," he said.
"He taught us also to always be there for each other. At the end of the day, you need to be able to count on family, and we were truly and still are very much a close family today."
For better or worse, sometimes it takes a near-death experience to remind us of life's fragility. For Kathi Ross and her family, this Father's Day will be a time to celebrate how her husband saved her son's life.
Her 6-year-old son, Lane, was pushing his bike into the garage in April when somehow, the family's SUV lurched forward and pinned him underneath the front passenger tire. Beneath him was his bike wheel, which was folded over "like a taco," Ross said.
"I started immediately screaming and praying at the same time," said the fifth-grade teacher from Catawba, South Carolina, who shared her story on CNN iReport.
Luckily, her husband, a police officer, had come home early from work. Chuck Ross was upstairs changing when he heard his wife scream and immediately ran downstairs in his underwear and bulletproof vest.
He jumped in the car and backed it off his son. Lane had lost consciousness, and his skin had taken on an ashy, purple tone by the time his father knelt and started performing CPR. Just when Ross thought it was over, her son started coughing up grassy-looking material.
Her son would later tell her that he remembers being asleep when he heard someone telling him to breathe.
"I woke up, and it was my daddy, so I thought I better listen!" he told his mother.
An ambulance arrived and took him 30 minutes down the road to Charlotte, North Carolina, where he was treated for lacerations to his kidney and liver. Miraculously, he was out of the hospital a week later and playing baseball a few weeks after that.
He still has scars on his legs and belly, a small price to pay for a miracle, his mother said. Now, the bond between father and son is stronger than ever.
Ross credits her husband's police training with saving her son's life. Had he still been a homebuilder, making much more money than he does now, he might not have known what to do. He joined the force after losing his job in the recession.
"A lot of the time, (police) get a bad name, but you never hear about the good they do," she said. "Their training helps them help people on a daily basis, whether they're in uniform or out of uniform."
Brewer speaks of her father in heroic terms, too.
Like many veterans of his era, he seemed to harbor guilt for having survived Vietnam and Korea. She once asked him whether he was a hero, and he told her no, because "only the cowards came home," she said. Before his death, she made arrangements for his burial in Arlington, at the veterans cemetery, and made it to his hospital room in time to tell him that he'd be in good company because "there are no cowards in Arlington, as all America knows," she said.
This Father's Day, she'll call her mother and brothers and toast her father's memory with a Bacardi and Coke, his favorite drink. Maybe she'll remember when he walked her down the aisle at her wedding even though he could barely walk and pulled back her veil, kissed her cheek and told her to "be good."
"Many of us ... are out of daddies at our houses. That doesn't make Father's Day any less special; in some ways, it means even more. I'm so blessed to have the memories of the father I had, even if we don't have him here anymore."
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