I wish I remembered exactly what it was, but I read a theory that actually made some sense, about the mother being dead, and Ted ending up with Robin in the end anyways, and would have allowed for the story to end with Ted meeting the mother, and Marshall winning the bet with Lily. The Marshall / Lily bet is really the only thing out there that has me wanting Ted and Robin together, and thinking it may be any kind of possibility.
But no matter the reason why Ted was the way he was, because she dies or because he's just tired of being alone, I agree with the poster that said his speech hit me right in the feels.