The episode's primary theme is the necessity of moving on from the past to embrace the future.
Ted delivers a famous, polarizing speech about love being "nonsense" but also "the best thing we do," arguing that even if it's unrequited or doesn't make sense, it's worth the pursuit.
"Eternal Flame" by The Bangles, which underscores the emotional climax where Ted resolves to move on so he can eventually meet "The Mother."
A heavily intoxicated Barney leaves the hotel and encounters two young men. He takes them under his wing to teach them "how to live," effectively passing on his "Playbook" lifestyle before he officially enters marriage.
The episode follows three distinct storylines occurring in the early morning hours before Barney and Robin's wedding:
While searching for a drunken Barney, Ted and Robin wander the beach and reflect on Ted’s past relationships. This culminates in Ted finally confessing why he broke up with Victoria: because he wouldn't stop being friends with Robin. The episode ends with the symbolic image of Ted "letting go" of Robin (visualized as her floating away like a balloon) to the song "Eternal Flame."