What is speical about Disneyland

I've been to Disneyland a half dozen time so far and it is really interesting.  I have a few friends who are huge Disney fans, but not into theme parks in general.  As I've send before I love theme parks of all kinds and now that I'm smaller want to see the whole range of them. I know I am just scratching the surface so far. 

I know there is something different about Disneyland for many reasons.  It is an interesting combination of the park, the history, and the customers. I've written before who people who go to Disney parts their whole life and have self nostalgia. 

Things I see every time I'm at Disneyland:

Custom and Group T-shirts
Honeymooners
Bachelorette trips
Celebration Buttons
Multi Generation Families
All different age groups
People doing a collectibles search
Crowds
People waiting for parades

I don't see these things on all my trips to other amusement parks. I need to go to more amusement parks and reassert. It just feels different than what I see at other places.