I have not read any of the responses to the rest of the thread. I only read the OP and felt a need to respond.
I too have read the bad 1st visit trip reports and wondered what the difference was between those experiences and my own. The OP proposes that having visited as a child may be the key difference. At first I totally disagreed. My first visit to WDW was in 2003 with my wife and two of her brothers. I was hooked (after being intially skeptical). We have been 6 times since 2003 and are now Annual Passholders. I love it...and I never went to WDW as a kid....
But then I thought....wait a minute. It's true I never went to Florida, but when I was 4, my parents drove out to California (from Minnesota) to visit relatives and we got to spend a day at
Disneyland. I was only 4 but I remember many, many moments from the little trip to Disneyland. The tea cups, meeting Pluto, the parade, and some rides that made me scared like the Haunted Mansion. So, I did visit as a kid!
Anyway, we took our 18 month old son to WDW last January and had a wonderful trip. He loved it and came back home able to say "Mouse!" when he saw Mickey around the house. Still does it too, now that he's 2.
My wife and I took a two day side trip to WDW this past July without our son and we had a great time. But I did miss having my son there. We watched Wishes both nights and I had the same experience as the OP (but my son wasn't there of course). I was thinking about my son and trying to sing along to myself and found I was all choked up and teary eyed, hearing the music and thinking about my son and my family. And it happened twice! Two nights in row! Geeze....what a softy I am!
Anyway, thanks for the OP, it got me thinking about things and remembering good times at WDW. My wife and son and I will be heading back soon for the Halloween Party. I can't wait to see what he thinks of WDW this time!
Eric