well, certainly it appeals to sixth graders in the sense that it's a cartoon and he and patrick and squidward are always embarking on rip-roaringly silly adventures, but if you really start to get into the characters, and know their nuances, they're remarkably consistent, and you can almost predict how they'll behave in a given situation. I don't know why i think it's so funny.
I like how they make Patrick so unimaginably stupid...i actually find myself getting frustrated with him sometimes, then i realize i'm getting angry at a starfish, and giggle like a maniac at myself...i like how spongebob is so blissfully unaware of everything else going on around him and yet somehow manages to live a life of pure innocence and gaiety, somehow insulated from the rampant sin in Bikini Bottom...i love how Mr. Crabs is so obsessed with money...to the point of absurdity...i love squidward and his "bert-esque" attitude toward life...and their episodes...they're written with such wit. I mean, the dream sequence one where SB is taking the driver's test and he's hurling toward the bottom of a cliff in a car during a driver's test, but then wakes up and realizes he's dreaming...but he's dreaming in the car, and then because he was sleeping ends up plunging over the cliff anyway, and then he wakes up again, and it just keeps happening over and over....that's comedy, dammit. A bit of a rip off of Luis Bunuel, but comedy nonetheless...
anyway...you should give it more of a try if you have the time...
s.
