Usually at 13, the world - shrunken to a few city blocks of cocoon-cozy familiarity - offers a safe, stable, unassailable haven.
Paradoxically, everything in a 13-year-old's world - an upcoming exam, say, or the best place to grab a pizza after practice, that new girl at school - no matter how trivial upon reflection, also takes on a life-and-death importance.
Or seems to.
Until reality sometimes encroaches on the sunny illusion.
"I was definitely scared at first," is how Flames defenceman Noah Hanifin recalls the stunning news that his dad, Bob, had been diagnosed with cancer eight years ago. "He had colon cancer and kidney cancer. A serious surgery and treatment.
"My dad and I are extremely close. He's been huge for me in my hockey. He'd take me to all my practices and games as a kid.
"When he got sick it was tougher for him to do things like that. It was so hard to see.
"And tough on my little siblings (brother Cole, sister Lilly) who didn't really know what was going on."