Just when you think you have seen everything in sports, you realize you ain't seen nothin' yet.
And some things you never want to see or see again.
The latest unimaginable occurred when a young man lost his life Saturday night under circumstances extraordinary even for the wild world of auto racing.
Of all the ways that the sport endangers people -- drivers in crashes, fans from car parts flying into the crowd, pit crews being sideswiped -- the latest might be the most difficult to comprehend.
Kevin Ward Jr. essentially jaywalked across a dirt track to confront fellow driver Tony Stewart and died when Stewart's car struck him.
That led to Sunday's debate over how much blame Stewart, a three-time Sprint Cup champion, deserves for the tragedy.
Was the 43-year-old Stewart responsible going all the way back to when his car bumped the 20-year-old Ward's car out of the race?
As Ward walked across the track waving his arms toward Stewart, was Stewart trying to drive close enough to scare him? Did Stewart attempt to swerve out of Ward's way? Did Stewart even see the pedestrian on the track?
Then there's the issue of Tony Stewart competing on a dimly lit dirt track near Rochester, N.Y., the night before competing in a NASCAR race in Watkins Glen, N.Y.
Stewart has been widely criticized for this schedule so let's stab at explaining his motivation for participating in the minor-league event.
Maybe the most applicable explanation was Barbara Bush's when her husband, former president George H.W. Bush, jumped out of a plane for fun at age 80.
"One might think that a man his age would grow up," she said. "I guess not."
One might think that Tony Stewart would grow up rather than continue to drive in these dirt-track events.
However, countless major-league baseball players wind up enjoying themselves on rehab assignments down in the minors. NBA players go back to play in playground summer leagues. NFL players would go back to play another high-school game if that were possible.
Stewart revisits his roots to race against drivers half his age because he can. Men -- women too -- do crazy stuff like this.
They volunteer to go to war. They eat a zillion hot dogs in 10 minutes on national TV during the Fourth of July. They jump out of planes at age 90, which George H.W. Bush also did.
Then there's the question of why Kevin Ward Jr. thought it was a good idea to walk across an active dirt track in a fit of road rage.
Maybe there's an answer for that one, too: once someone starts racing autos, there's no telling what else he'll do.
Auto racing on any level is nuts to begin with. All other bets are off once a driver climbs into a speeding bullet with other speeding bullets buzzing around him.
Considering that Kevin Ward. Jr. started racing go-carts when he was 4 years old, perhaps no risk was too risky for him.
Now consider that Tony Stewart originally decided that despite Ward's death, he would race Sunday in the Cheez-It 355 at Watkins Glen, N.Y.
Talk about the definition of distracted driving.
Greg Zipadelli, the manager of Stewart-Haas racing, initially described Stewart's call as "business as usual." At a Sunday morning news conference, he finally announced that "Tony will not race today."
Ontario County, N.Y., sheriff Philip Povero portrayed Stewart as "visibly shaken." Zipadelli said, "(Tony's) going through a tough time."
Now authorities will have to determine Stewart's intent when his car struck and killed Ward.
Seriously, these developments are enough to make a sports fan fear what else we haven't seen yet.