How I Met Your Mother co-creator Carter Bays talks fans' theories and series finale

The How I Met Your Mother series finale airs Monday night, and the only solace we can take in these dark times is that we get one last round of spoilers, previews and teases from the cast and crew.

Co-creator Carter Bays spoke to E! Online and one of the topics on the table was the fans' numerous theories about the ending. The most popular, of course, is that The Mother is dead in 2030 when Ted tells the story to his children. But Bays said that he and co-creator Craig Thomas never planned for such fervor.

"I don't know if we set out to do it, but it has definitely been interesting walking around for nine years with all these secrets in our heads," Bays said. He also described his favorite, craziest fan theory. "I've always enjoyed the theory that the world of 2030 is a post-apocalyptic wasteland. Like where the Narrator says, 'Marshall and Lily got married under this beautiful tree,' and then the kids are like, 'What's a tree?' and the Narrator just starts sobbing."

E! Online also asked Bays what he hopes fans take away from the show once the final credits roll.

"I hope people feel the love that went into making not just this finale, but this entire series," he said. "This is the ending we've been writing toward from the beginning. There will be laughs and tears along the way, but ultimately it's a very fond farewell."

Are you emotionally prepared for the HIMYM series finale? Let us know in the comments below.