Though many of the 33 Chilean miners have agreed to keep the details of the 69-day ordeal a secret, others have started to share their reflections and insights.
Sepulveda spent much of this weekend falling in love again with his wife, Katty, and dancing with his daughter, Scarlette. When ABC News came to visit, he read from the goodbye letter he'd written for his son, Franco, when he thought he was going to die.
"I will miss you, son," he wrote. "But I am tranquil and happy, because as I leave this earth, I know you will be in the good hands of your mother."
In his first TV interview since leaving the mine, Sepulveda, 40, said that he feared leaving his kids and wife alone.
"That was a familiar thought," he said. "But every time I thought of that, I immediately returned to where I was."
A 'Rocky' Reunion: Sepulveda Shows Thanks
After being rescued, Sepulveda ran, yelling and cheering and hugging everyone in sight. The world media quickly nicknamed him "Super Mario."
He told ABC News that he admired President Sebastian Pinera for his efforts in rescuing "Los Treinta y Tres" -- those 33 men.
"I believed in our president," he said an hour after being released from the hospital. "He is forceful and he's rich. Nobody has given him what he has. He's a workaholic."
Sepulveda was so overwhelmed with emotion after he emerged from the mine that at first he didn't recognize Pinera. "I looked for everyone and then I realized I am in front of our president," Sepulveda said.
"It was so emotional to hug the president that I repeated it twice more because really our president played a fundamental role, and it was very humane of him to put in place the technology and resources to make the rescue possible."
Mario Sepulveda, Exuberant Chilean Miner
To show his appreciation, Sepulveda handed out rocks -- souvenirs from the mine -- to workers and Pinera.
"I was thinking, 'How can I show my appreciation for the president and all of the people who did things for us?' ... Suddenly it occurred to me, 'Ah, yes. Rocks!'" he said.
After the cave-in, he said the miners set off some leftover explosives in the hope that someone on the surface would hear the noise. The blast loosened the rocks that he gave as gifts.
"Those gifts have a special sentiment that is personal and spiritual, that represent the 33 miners that were in there," Sepulveda said.
'Let's Get Out of Here!'
He said that on the day of the mine collapse, "I was wearing ear plugs and a hard hat, so I could barely hear."
"But I felt something odd and another miner started yelling, 'Mario, it's a cave-in.… Let's get out of here!'"
Sepulveda started looking desperately for a way out. He climbed a ladder up a ventilation shaft, but the ladder ran out, and rocks started showering down on him.
"I told the men, 'There's no escape. We need to remain in this shelter. God is here with us. Whoever wants to save themselves, take his hand,'" he said.
During those first few days, Sepulveda said, the men often screamed, fought and cried. "You have everything going through your mind: You fear, you cry and you suffer. You wonder, 'Is anyone coming to save us -- or not?' But doubt always was a passing moment, because we had faith. Every day at noon, we would pray. Every day. Down there, we were all … one religion."
Reports have surfaced that the men worried about cannibalism. Sepulveda said he never considered that, he simply hoped to die in his sleep. He even prepared for it.
"One night, I gathered all my things, my seat belt, my hard hat, and I thought, 'When I die, I want to die as a miner and when they find me, dignified, the world will say, "A miner died with his head held high."'"
"The miner has something very special," Sepulveda said. "Given all of the work circumstances that we've always had, we've always been very united in all aspects. The truth is, real truth is, we laughed a lot. We even had a good time because that was the way to stay alive."
Rescue on the Horizon
One week after being buried alive, the miners started hearing drills cutting through the mountain. Most of the drills failed to reach the shelter. But then, on day 17, one broke through.
"It was a miracle. We hugged, we cried, we thanked God. We banged on the drill for an hour, hoping someone up there could hear us. We then tied little notes to the drill," Sepulveda said.
When rescuers pulled the drill back up, they found a crumpled piece of paper that read: "We're alive, in the shelter, all 33 of us."
But it too an additional seven weeks for the miners to be lifted out. During that time, Sepulveda was their cheerleader.
"I would tell them, 'Look, compadres, we will be fine, we will be happy and we'll blow out of here.'"
Cameras sent down by the rescuers showed Sepulveda's approach to the world: a mix of faith and laughter. Sepulveda had become a clown and a jokester, even caught on tape dancing around with the Chilean flag. To the outside world, he was a light-hearted tour guide in a dark underworld.
Keeping the Faith
The first thing Sepulveda wanted to do when he left the hospital was go to the beach. No one who watched had any idea that they were about to see him strip down without warning and frolic naked in the water. With his little boy at his side, he dropped down to his knees and gave thanks.
"I adore you, God," he said. "And I promise I will never leave you, just like I promised you when I was buried alive."
Before the ABC News interview ended, he said: "Life is short. In one minute you can lose it. In one minute it can all be gone. Don't worry so much about money. Live your life. Live every second of it."
The Most Spirited of the Chilean Miners
As those rescued last week are celebrating their second chance at life, 300 other miners who were not trapped and will no longer be able to work in the now-closed mine are protesting in hopes of receiving compensation for their lost income.
Sepulveda said he would return to the mines under certain conditions so he could finance his children's education.
"If a mine offers safety [and] a good contract [where] I will be respected as an operator, I will work again," he said. "I was born to work, to give my family education, safety and health, and give a good time to my kids. That is my dream. That is my project."