But the idea that your child might be so sick that they didn't survive, is something that no parent even wants to think about for a second.
Still, life can sometimes be cruel, and when Bill Kohler's son fell ill, conversations about death became inevitable.
Ayden was only nine years old when he was diagnosed with a rare, aggressive form of brain cancer called diffuse intrinsic pontine glioma (DIPG).
Children who are diagnosed with the disease usually die within one year, writes the US National Institute of Health.
But the bad news doesn't stop there. Ayden didn't just have one tumor on his brainstem—he had two.
As every parent would, Bill tried to do everything in his power to try to save his son, but nothing could have helped.
When Bill finally accepted that his son wouldn't survive, he promised his son one thing: that he would do all that he could to make Ayden's last days on earth as good as they could be.
He brought Ayden to meet his favorite wrestling heroes, he brought him on hunting trips, and he threw a 10th birthday for him.
"We looked at the day, and we looked at how we could make that day the best we could," Ayden's mother Jennifer Zeigler told Public Opinion.
But then the time that the all dreaded finally arrived. Ayden couldn't walk and even had trouble breathing.
He no longer had the energy to keep up the fight, and he said to his father, "Dad, I gotta quit."
These are words that no parent ever wants to hear their child say, and how could you possibly respond?
Bill answered the only way he knew:
"I'll make you a promise. If you've fought as much as you can and as hard as you can and you feel you fought that hard... I promise you, it's okay to quit."
Ayden died on March 22 this year, only seven months after being diagnosed.
Ayden's final wish?
"If people gather to remember me, I want them to dance, sing, and take group pictures," Ayden said. "And if anyone asks how I want to be remembered, please say happy, funny, athletic, wise, fighter, caring, and selfless."
Even though Ayden has become an angel does not remain on earth, his memory lives and remains forever.