There is a dissonance underlying every World Series. Every year we watch as two very good, sometimes great teams vie to determine Major League Baseball’s champion. Even when a 2006 Cardinals team slips on through, baseball’s final showdown remains the pinnacle of the sport. This is as good as it gets; it may never be this good again.

That is the uncomfortable lesson at the heart of October. Enjoy this now, because who knows how long this will last. Potential juggernauts can be disemboweled in front of our eyes. Dynasties get broken up brick by brick. In one moment, Matt Harvey is standing on the mound of Kauffman Stadium, ready to throw his first pitch in Game 1 of the 2015 World Series.

Two years later, he has a 6.70 ERA.

In baseball, greatness is fleeting. It hinges on sinewy elbow ligaments, cautious owners, and perfidious narratives. It often takes years of build-up to make one postseason, let alone the World Series. A title is dependent on long-term vision and small sample size variance, probably in bewilderingly equal amounts. Continuity can be a maddening pursuit.

That 2015 World Series was like a work of fan fiction. Two long-dormant franchises suddenly rose up, peaked as their window of opportunity opened, and tossed off their loserly ways.

The Royals had done this the year before. In 2014, they inched to within a Madison Bumgarner Hulk-smash from winning a championship. (They also needed an Oakland A’s collapse in the wildcard game to avoid becoming a postseason one-hit wonder.) A return trip was entirely realistic, for everyone except PECOTA.

The Mets, however, were the lightning bolt that struck the National League. They were still spinning their wheels through the end of July until a few trades swung their fortune. Yoenis Cespedes turned their floundering offense into the league’s best following his arrival from Detroit. Their bullpen was no longer a mess, even after Jenrry Mejia was suspended for failing a second drug test.