What really happened between Ted & Robin in Central Park?

I will begin by stating that the show "How I met Your Mother" is complex and can be enjoyed on a simple level or a more complex one. On a simple level, viewers accept at full face value anything and everything that the show is leading up to, chiefly that, because of its title, the show was about Ted meeting the one true love of his life, the "mother" of his children. In reality, however, the title was the only real basis for that assertion.

Said Josh Radnor (Ted) in an interview:  "I thought the title of the show was always a bit of a fake-out. It was more of a hook to hang the thing on. Really it was more about these are the crazy adventures and these are the lessons I had to learn before I met your mother."

Once the title's role in defining the direction of the show is dismissed, one might think that that the producers' intentions become open to a wide array of interpretation. We find out in the shows next-to-last scene that this is not the case. In this scene, after Ted finishes telling his kids the story ostensibly about how met their mother, the kids call him out on it, telling him that the story was not about him and Tracy but always about him and Robin. Then they urge him to pursue that relationship, since they love their dad and they love Aunt Robin, who has apparently been a part of their lives for quite some time. Since this scene was film very close to the beginning of the show, it has obviously been the plan of the show all along.

In that same interview, Radnor said the the writers, meaning the show, dropped hints as to how the show would turn out:  "It's not that people cracked some code," he said, acknowledging that some viewers correctly predicted Ted would end up with Robin. "They were laying that in, so that it would be discussed and slightly less jarring for people."

I've read many comments about the ending, and many viewers will never admit that the show was ever about Ted and Robin, despite what everyone associated with the show says.

If you are one of those, you can stop reading this now.

For the rest of you, I wanted to talk about what what I believe to be one of the hints Radnor alluded to, the scene in Central when Robin was desperately trying to retrieve a locket she had buried there many years before while visiting New York with her father.

Robin was having serious doubts about her upcoming marriage to Barney, and it didn't help Barney's case that he refused to be with his distressed fiancé in the park, opting instead to play laser tag with his future father-in-law. Still, she decided to let the universe to decide whether or not she was doing the right thing: if she was able to find the locket she would accept that as a sign that she should marry Barney despite her concerns. 

What Robin didn't know--or rather, what she had forgotten--is that the she had already retrieved the locket years before. At the time, she had revealed to Lily that she was planning the wear it on the day she married Ted, but since Ted didn't want to marry her, she would take the locket with her on her move to Japan. And the reason she was moved to Japan was to not have to deal with Ted, who was dating Stella at the time.

When Barney didn't agree to come to Robin in Central Park, she called Ted to come and provide the emotional support that Barney would not provide. Ted was supposed to be on a job interview, but opted instead to join Robin without knowing the reason she was there. 

Now Ted loved Robin and would do anything for her, and almost anything to end up with her. But the one thing thing he would not do is come between her and Barney, despite his feelings. He could not hurt Barney that way.

So when Robin told him that she was willing to let the universe decide whether or not she should marry Barney, Ted attempted to downplay the role of the universe in their lives, despite the fact that he had always believed the opposite.

And when she found the box that once contained the locket but was now empty, she became even more distraught over her impending nuptials. 

Ted tried to allay her fears, but the last thing he said to her during that scene is revealing: "Maybe we don't need the universe to tell us what we really want. Maybe we already know that, deep down."

Why would Ted say "deep down"? What does it add?

Now, you can look this up yourself, but "deep down" is an idiom that refers to our true feelings, not the feelings that others attribute to us." So if Robin has deep down feelings, it certainly casts doubt on what we believe her feelings are. 

So how does Robin respond to Ted's words? She takes his into hers, and not just in the usual way of hand-holding. Rather, she interlocks her fingers with his. Again, you can look this up yourself, but according to experts in body language, interlocking fingers expresses the desire for a deeper, more intimate relationship.

And if that wasn't enough, she then gazes into Ted's eyes in such a way that anyone possessed of the slightest amount of perceptive ability could tell that she was in love with him. 

Ted picked up on this and withdrew. And, as he later related to Lily, as a result of this encounter he decided to move to Chicago. It can't because he was love with Robin, for he had known that all along, but because he now realized. that Robin loved him. As long as he remained a part of her life he would be a threat to her marriage to Barney.