When I first saw EPCOT Ctr. in full, I was about 38 years old. I was there in February 1983, it was 4 months old and to be honest is was a little disheveled and unorganized. (unless both those words mean the same thing)
When I went two years later, I saw them all. The only one I'm not sure of is The Seas. It seems like I remember it from that trip, hydrolaters and all, but I'm too lazy right now to look it up. I was the quintessential Disney tourist back then. I didn't know there was a ride in SSE. I didn't know what was there (pre-internet) and what it was all about, so in the Land, I didn't see the Food show, don't remember the name (first one, Kitchen Kabaret maybe?) because I didn't even know it was there. On the other side of the park I did go to SSE (Walter Cronkite edition), Energy, Wonders of Life (didn't know about Cranium Command then either), Horizons, and World of Motion. In Imagination I rode the ride along with Dreamfinder and Figment and saw that atrocity called Captain EO.
I truly didn't appreciate what I saw on that trip until I think about what is there now and I understand the quality and talent it took to design and build that park. Those are the things that made EPCOT what it was. As I think back at it, I think that pretty much everything with the exception of the original Energy Pavilion would be totally relevant today and would still work. Omnimovers were our friends and it was that something that you didn't find anyplace else.
I apologize for possible mistaken names and possible mistaken memories, it was a long damn time ago.