I watched the last episode only a few hours ago and came to this site because I thought, just like you, that the ending was a let-down. I was glad to see your post as I was wondering how that ending had been processed by others.
I like how you vividly went through the possibilities. I mean, the end is so removed from the brilliance of the previous episodes that the craziest things should be considered 😉
Here is my working theory, developed for my own need for closure and because I refuse to think that writers who have led us through such a wonderful journey would completely lose it at the very end:
I'm telling myself that Yan Ze and He Xin Liang didn't get together and really dated. Yes, they did the running-to-each-other thing to finally declare their love, but then reality kicked in. He had to go to the US (because you know, dreams) and the long distance relationship and promise to wait wasn't really an option for 4 years. Whatever the reason, the relationship stopped before it could really start, she mentions that they broke up. They didn't keep in touch because, well, breakups at that age and when you're supposed to move on with your college life and life in general aren't exactly the best conduit to friendship, especially if you're thousands of miles apart.
As time passed, she couldn't move on because of the way she lived her side of the love story. She's likely to have gradually discovered most if not all of the things he did for her. Moving on from such a slow simmering love while it never had the chance to get messy is harder. Every quarrel with him (and they had many) is revisited from a new perspective. She surely kicked herself repeatedly because she knew she could have had a relationship all those years instead of pining for her idea of a prince (desk-mate). Because of all that, she kept He Xin Liang as a paragon, the perfect one for her, making any other guy she might have dated after high school lacking.
At the school reunion, she was hoping to see him again, not necessarily to get back together but maybe to quell that need for proper closure, to really go over what it is that she'd understood he meant to her. When she shouts out of the cable-car, it is as if she'd never really told him she loved him.
Come to think of it, I believe the ending scene doesn't insult us too much as there's no kiss. It's initially a hug, one two childhood sweethearts or lovers-that-could-never-be might share after finally getting an opportunity to see each other again.
Because the story was told so that all the disasters in their love story were lived by him, because she'd been in his heart from their pre-teen years, it's easy to believe that he remained stuck on her while abroad. However, the possibility of having children and a wife back in the US only goes away when he grabs her and runs.
The answer comes in the run, initiated by him. He knows she's single at this time and the run is a throwback, a sign he wants to go back to the time or at least that relationship in which he would drag her to one place or another.
There! Now I can move on with my own life. Jeez, having to complete stories ourselves is exhausting...
HCS:
