My first time going was when I was 5 and it was awesome. Animal Kingdom had just opened up and kali river rapids was soft opened. We just kept riding and riding it since there wasn't a line.
I obviously don't remember stuff from back then super well but I was definitely old enough to appreciate it and have it influence me. I wanted to grow up to be a Disney imagineer so badly!
Now my trip to Kennedy Space Center when I was 8, now that was something I wasn't old enough to appreciate
You probably have a better memory than most! I first went to Disney when I was 8 and I barely remember it at all. The biggest thing is not being able to experience some rides because of height