For me, the joy of Pee Wee's Big Adventure can be summed up in one line: "I'm a loner, Dottie. A Rebel." The joke of that line is that Pee Wee delivers it like he's James Dean, but he's the opposite of brooding cool - he's a manchild who lives in a wonderland of toys, one who is obsessed with his bicycle and seemingly completely asexual. But at the same time, he is a loner - he goes on his Big Adventure without any constant companions. And he is a rebel; he lives his life like he wants to live it, without caring at all whether anyone thinks he's weird.
The first Pee Wee movie was co-written by Phil Hartman, and if you're familiar with his work on Saturday Night Live, then it's obvious that "I'm a loner, Dottie" was probably his work. Most of Hartman's characters looked like Eisenhower-era authority figures, but they were secretly absurd weirdoes. That line is a great example of that style: if it was said by a brooding young man, it would be dramatic, but because it's said by Pee Wee it punctures the earnestness of the sentiment. But again, that line is not completely a joke, because the movie respects Pee Wee as a character. Big Adventure is a celebration of loners and weirdos because it gives them the same dignity that a more traditional rebel would get.
Unfortunately, Phil Hartman didn't help out on Big Top Pee Wee, the 1988 sequel to Big Adventure, and his light touch is sorely missed.
Although Pee Wee wears the same suit and talks in the same voice in the two movies, a lot of of his fundamental traits are different in the sequel. The Pee Wee in this movie is not asexual - he's not only engaged to a real live female but he cheats on her with a circus acrobat. This Pee Wee doesn't live in a home that's full of Rube Goldberg machines, he lives on a farm with a talking pig. His beloved bicycle is nowhere to be seen, but he does have a tractor he can loan to the circus that got stranded in his front yard by a tornado. Big Top Pee Wee tries to emulate the first film's tone, and to some extent it succeeds in being whimsical, but it definitely isn't as magical; the ageless inexplicably rich weirdo from Big Adventure is a very singular character, but the farmer who wants to join the circus is merely eccentric.
Big Top Pee Wee still has its charms: most of the circus folk who find themselves suddenly living on Pee Wee's farm are as well drawn as the oddballs that Pee Wee met on his road trip in the first movie. And I suppose I can't blame Paul Reubens (who plays Pee Wee, and who co-wrote both movies) for wanting to play a character who eventually gets the girl. But even though Big Top Pee Wee is 80% as good as Big Adventure, the twenty percent that it's missing is enough to mean the difference between being an all time classic and an okay kids movie.
I think about "I'm a loner, Dottie. A Rebel" quite a bit, and whenever I do I feel less alone. (A big part of that is because my friend Lola and I both independently put that quote in our facebook profiles, so whenever I think about it I think about her.) It might sound like a contradiction, but that line offers up a brotherhood of solitude - it unites all of the people that don't have anywhere else to fit in. In contrast, Big Top Pee Wee is about a guy who doesn't fit in where he lives, but who finds brotherhood when a carnival full of misfits lands on his lawn. It's also about an outcast fitting in, but I feel left out of it entirely - I'm never going to join the circus, and I don't have much in common with a strong man or a dog faced boy. Somehow, by putting more effort into making Pee Wee fit in, Big Top Pee Wee feels less inclusive. I think the truth is that Pee Wee was always meant to be a loner, and when he joined a team he lost part of what made him special.