So the in Holes towards the end, it in a way talks about fate or good luck, maybe even a curse because of the pig stealing great-great-grandfather. It doesn't necessarily talk about the curse being true, but coincidently the "curse" broke off. "Stanley's mother insists that there never was a curse. She even doubts whether Stanley's great-great-grandfather really stole a pig. The reader might find it interesting, however, that Stanley's father invented his cure for foot odor the day after the great-great-grandson of Elya Yelnats carried the great-great-great-grandson of Madame Zeroni up the mountain." The book gives the message of curses aren't real but fate can think otherwise, the grandchildren of Madame Zeroni and Elya Yelants. Then again it could've all been a coincidence and the fact that Stanley had the will to bring himself together and devise a plan to help himself and Zero bringing him redemption could be the meaning. But let us stick with the curse and fate meaning shall we?
Chris Jericho from The Best in the World felt he had a curse too except his doesn't have an ending to it. On a return to wrestling he feels something always goes wrong, this time he didn't really see to it as a it being curse worthy. "Now those of you who have read my previous books might be think the match was Jericho Curse worthy. It wasn't a bad match, it was just kinda there." Usually he will say how his returns had something wrong happening, but he didn't see it too bad this time, just mediocre.
Both books though have a thing with curses, though I realize now why it is different. One is non-fiction and in reality, curses might not be much of a thing, just repeated coicidences. But in fiction things aren't a reality, the curse might've been real in the book letting it fade away once the promise was done when the grandson carried the other grandson. That's why their curse lasted so long because the promise was never done, but once it was completed everything went their way. So I think the difference was just the genre, unless curses are real.