He overslept that day.
The phone rang and instead he was called away.
He decided to do something else that day.
Take a hike. Ride a bike.
See a movie. Visit his sister in New Jersey.
His car failed.
The right tire went flat.
He left his wallet and had to go back.
The Instructor called in sick.
It wasn’t a cloudless beautiful day.
That damned small little plane didn’t break.
If only you were still here today.