Stanley is the only passenger, aside from the driver and the guard, on the bus to Camp Green Lake. He sits handcuffed to his armrest, sweating in the heat. Stanley and his parents had tried to pretend that he was actually going to camp like rich kids, and Stanley remembers pretending as a kid that his stuffed animals were going to Camp Fun and Games. He hopes he'll make friends and swim in the lake when he arrives. Stanley doesn't have friends at home, as he's overweight and the object of merciless bullying at the hands of teachers and kids alike.
Stanley's reverie sets up camp as a marker of economic success, while his family's attempts to pretend that Camp Green Lake is a real camp indicate that they desperately do want to do better economically. Note that Stanley is already the victim of cruelty and unkindness; this suggests that he may be coming to camp already unwilling to stand up for himself.
The narrator explains that Stanley is innocent; he was convicted because of his no-good-dirty-rotten-pig-stealing-great-great-grandfather. Supposedly, Stanley's grandfather stole a pig from a "Gypsy" and she cursed all of Stanley's descendants. The family, of course, doesn't actually believe this, but things do seem to go wrong a lot. Stanley's father is an inventor, though none of his inventions have been successful.
This explanation introduces the possibility that Stanley is the victim of bullying (and his dad is an unsuccessful inventor) not because of any fault of their own, but because of something well outside their control. Similarly, this also suggests that Stanley's family is paying for his great-great-grandfather's transgression, illustrating one way that justice is served.
Stanley's mother often points out that not every Stanley Yelnats has been a failure—Stanley is the fourth Stanley Yelnats—and this is technically true, as the first Stanley made a fortune in the stock market. However, the bandit Kissin' Kate Barlow robbed him as he tried to move to California. Stanley thinks this is kind of cool. His reverie is interrupted when the bus arrives at Camp Green Lake.
The fate of the first Stanley Yelnats suggests that the possible curse on the family doesn't necessarily mean that no family members can ever experience success—their successes just aren't things they get to keep. This is another way that Stanley's family becomes disadvantaged economically.