Heck, I remember when Magic Mountain opened for the first time (SeaWorld was part owner), and going in 1971.
I do miss the Spillikin Corner, the back area where Apocalypse is now, it was designed as the more Adult area, served Beer (only in that area) and had a lot of tradespersons making crafts for sale (and some are still there, like the Candy Kitchen), and a nice train ride. In 1971, they did have a deal to use the Looney Tunes characters, but as only good for one year, after which, MM decided to make their own character, the Trolls.... I also miss them.
Yikes, did you know that one of the first performers at the park was Barbra Streisand (now the venue is called the Golden Bear Theater). Also most of the opening attractions were made by Arrow, which was a main outside company working with Disneyland.
I also remember the big lake about where Hurricane Harbor is now, nice seating and some interesting shows, and fireworks were held there.
And now a piece of history is leaving, the original Dolphin Show theater, that got converted to the Stunt Show area for the new Dark Ride coming next year.... (Also interesting to note, Knott's Berry Farm also had a Dolphin Theater about where Pacific Scrambler is located today).