Rapinoe was one of three U.S. players to miss their penalties in a shootout that ended 5-4 in favor of Sweden after the game was scoreless through regular and extra time.
Asked what she was thinking when she stepped up to take her penalty, Rapinoe said: "I'm gonna score. Back of the net. Always."
And what was going through her mind after she missed?
"A sick joke," Rapinoe said. "That's why I had that smile on my face. Like, 'You got to be f---ing kidding me. I'm going to miss the penalty?' I honestly can't remember the last time I missed a penalty. Not in a game for a very long time.
"But that's the way it goes. I've definitely thought about that before -- it's always a possibility when you step up there. But I thought I was going to make it. I thought everyone was going to make it."
Rapinoe correctly remembered that her last missed penalty for club or country came in 2018, when goalkeeper Aubrey Kingsbury made a save against her in the NWSL.
Before the World Cup began, Rapinoe announced she would retire at the end of the 2023 NWSL season, making this summer's tournament in Australia and New Zealand her final World Cup.
Rapinoe made her USWNT debut in 2006 and was part of the World Cup-winning squads in 2015 and 2019.
"I feel so lucky and so grateful to play as long as I have and been on as many successful teams as I have, and be a part of a very special generation that has done so much on and off the field," Rapinoe said. "It would be hard to feel disappointed in any type of way.
"Obviously there's the immediate disappointment of being out of the tournament, but I'm OK. I'm ready in a lot of ways to be done and I feel at peace with that."
Rapinoe was moved to tears when asked to reflect on her World Cup.
"I've loved every bit of my career," she said. "I'll miss it to death, but it also feels like the right time and that's OK."
"It's some dark humor, me missing the penalty at the end of this game," she added, laughing.