I really don't get it

Last night's episode of HIMYM, "Time Travelers," was the strangest episode I've watched. I just don't understand the episode at all. I mean, the promos were interesting; I thought multiple Barneys (and Teds, I guess) would be awesome. And he was (they were?). It's just that... I don't get the point of it. All of that was Ted's hallucination and that he was daydreaming about an (unimportant) event that happened 5 years ago. He was all alone, and I guess that's sad, but nowhere near oen of the saddest moments in the show's history as some people seem to think. It wasn't funny, and I feel like the writers were trying too hard to make the episode feel sad. The show does that very well, going from funny to sad in the next scene, but this episode was not that at all.

How is Ted going to his future wife's apartment crying and telling her he loves her 45 days before he met her beautiful? I think that's just desperate. The whole episode makes Ted look extremely desperate, and sad in the wrong say. I just...I just don't get it. I feel like this episode was thrown in for a filler. It has nothing to do with the previous episodes, and I don't see this episode having any relevance in future episodes. I really hope to be proven wrong, though.

There are quite a few people on the internet saying that this episode supports the theory that the Mother is dead. That would explain why Ted wanted the extra 45 days so much. But I don't think the writers are that cruel. Plus, it still doesn't make this episode any good.

Side note: the Teds and Barneys' a cappella at the end was amazing. The only good thing about this episode.