I got lucky... my first trip to Disney was in 2005 and I picked up The Unofficial Guide to Walt Disney World and read it cover to cover before we got there. Why? Because when I was a kid I used to go into travel agencies and lie, telling them we were planning a Disney trip and my mum had asked me to pick up some brochures. I always got the BEST books that way (bit fat ones intended for serious trip planning), and I used to read them cover to cover, knowing perfectly well that we were never going to go to Disney. So, the 2005 trip was the fulfillment of a childhood wish, and I just wanted to spend some time before the trip dreaming again, like I used to when I was a kid.
Naturally, we followed the touring plans in the back of the book and had a terrific time. And since then, it's just been a matter of adapting to the changes as they come along (though I no longer buy UnOfficial Guides).
And I think I got
especially lucky with regards to the way Disney World has trained me to plan all my other, non-
Disney vacations.
First Universal trip? I planned it like a Disney trip! In retrospect, I overplanned, but hey - a little overplanning never hurt anyone. And even though the Wizarding World had just opened, we were still able to see and do everything we wanted and dodge almost all the crowds, too.
First trip overseas (to London)? I planned it like a Disney trip! No standing around asking each other, "What do we do now?" No confusion over the subways. No crowds. We knew where we were going and when we should be there, and how to get there, too. Tickets and accommodation all purchased in advance. My daughter had been once before with her grandma and her one request was, "Can we see Madame Tussaud's?" Because when they'd tried to go, the line to get tickets had been all the way to the end of the block and Grandma wasn't having any of that. I did some research, figured out the lowest crowd days and how to get there for opening. We had a terrific time!
Basically, Disney has taught me how to plan a successful vacation. I think my whole family has benefited because of it. No matter where we go, I'll plan it like a Disney trip.
(
Important caveat - no battle plan ever survives intact. Every plan I've ever made, has had to be adapted on the fly. But being prepared, and knowing what's going on, makes being flexible and spontaneous SO much easier.

)