Donna: If we’re meant to be, then we’ll end up together.
Eric: No. The way we end up together is by SAYING we’ll be together, and then BEING together.
This might just be one of the most profound moments in the show. As a teen, Eric saw that he was looking for more in the relationship than Donna was. He wanted forever. He was in it for the long haul. She wasn’t. And because of that difference they broke up. It was the smartest thing I have ever seen him do. He gave her up not because he didn’t love her but because they weren’t loving the same way. She even says “We’re together now. Isn’t that enough?” She is only in it for now, until a better offer comes along. In the form of another guy, or a full ride scholarship, or an internship, or a job. It’s fine for her to want those things but she should never have strung Eric along for 2 years believing they would eventually marry. No it wasn’t discussed. But it should have been. They were kids, playing at being adults.
And look at what Eric said again. That is how a relationship works. Donna believes in fate. Eric believes in choice. Loving is a choice everyone makes. Sometimes that’s easy, and sometimes it’s hard. I think Kitty tolerating Red is what taught Eric that. Whereas Donna saw her parents fight, and leave. They never resolved things. They ran from them. From their own promises to each other. If it wasn’t easy they didn’t bother. She learned that from them. This show really had some fantastic aspects to it.