As a lifelong Disneyland visitor, and space enthusiast, I may have some insight on this question. At three years old I made my first trip to "The Happiest Place on Earth," and have experienced the park as a child, as a teenager ditching school with her best friend to ride rides, as a snarky young adult pondering visitor's wardrobe choices while people watching (really, stilettos? or, really, did you even change out of your nasty pajamas from three weeks ago?), and now as a mom of two young boys growing up with the park themselves. A funny thing happened, though, on my last visit.
A tradition for my birthday happens to be a trip to the park (that is why I know I went there at three years old). Never lovelier, Disneyland in mid-September empties its summer bloat of visitors as children make their way back to school. I looked forward to this, probably twenty-somethingth birthday celebrated at the park, but the first ride set the tone of my day. Let's just get this out in the open. I HATE THE PETER PAN RIDE. I hate the claustrophobic line. I hate the fact that that freaking lame ride has such an enormous line.
I ended up having a fine enough day, but my children, who still nap, began wearing thinner and thinner. Four or five hours in, my three year old's eyes glossed over and he was doing a pretty good impression of a Haunted Mansion zombie spook. My little one, barely two, through himself into limp bodied fits and tried to weave his way to the front of every line between the legs of Japanese tourists.
So, Happiest Place on Earth? Very subjective. Seems to me there are more tantrum filled tears than smiley-laughs come 4pm on Main Street, and not just from worn out parents.