That job you should have taken. That girl you never should have walked away from. Those moments with long-lost loved ones.
Or, far too often, that time your beloved team was at its apex, the best assortment of talent and run of success you ever saw.
Astros fans are lucky today. All due respect to the legendary Lou Gehrig, despite the dire and daunting circumstances that brought Astros fans to this place, they are the luckiest fans on the face of the earth.
They get one more ride and, if you please, they should appreciate every second of it. It will be gone soon.
George Springer, Josh Reddick and Michael Brantley all are free agents after this season. At best, given the economic hit the game is taking this year, the Astros can sign only one of them. Maybe none.
Yuli Gurriel will be on the market, too, and pushing the back-end of his 30s. And by 2022, finances, free-agency and age could well see the Astros no longer having the likes of Springer, Reddick, Brantley, Gurriel, Carlos Correa, Brad Peacock, Justin Verlander, Zack Greinke, Lance McCullers, Joe Smith, Ryan Pressly and Roberto Osuna.
Yeah, it goes that fast. But for now, baseball is back and so are the Astros.
Cherish the Last Dance -- and consider yourself lucky that at least you know it's here.
Appreciate it all in 2020. Appreciate a team that may well have one more World Series run left in them.
Sure, there is young talent that could be integral moving forward. Sure, the Astros may not miss a beat as they transition to a new era. Namely, Myles Straw and Kyle Tucker are superb talents who could keep the beat going.
But the once-mighty Astros farm system that led to this run no longer is as strong. And who knows when it comes to pitching prospects? Who knows also how new management will construct the team or even who will be the club's manager beyond this season.
But what we do know: baseball is back. MLB commissioner Rob Manfred finally establishing a 2020 season on Monday was by no stretch the perfect resolution for the game.
When it comes to the Players' Association, labor peace, financial stability for owners moving forward and especially goodwill between all involved, baseball's pause has been an absolute mess.
But what it did do was give Astros fans one last chance to strap in and ride with a club that should be among the favorites to win a world championship in 2020.
The Astros are in fact the best-equipped team to make a run through the 60-game schedule. Not only do they have a veteran-laden roster that has been proven, they have top-end veterans in Greinke and Verlander, who don't have to worry about load management or arm fatigue. They have McCullers, coming off an injury season, not having to put the stress of a 162-game grind on his arm and shoulder. They have a deep bullpen, and obviously an abundance of offensive talent. They have a veteran manager in Dusty Baker. Throw in the fact that the Astros won't have to deal with the wrath of fans everywhere they go in the wake of the 2019 sign-stealing scandal, and they could not be in a better place.
Soak it all in. And consider yourself lucky. You get one more dance.