Why would anyone want to go on Survivor? Living on a remote island for multiple weeks with little food or comfort does not sound pleasurable. Once you add psychological warfare to it, it becomes almost(?) torturous.
We can divide the contestants into three categories: The first want adventure. The second are attention hogs. The third really, really like Survivor.
In recent editions, these "superfans" dominate the casting, but one of the first was John Cochran, a Harvard law student (and giant nerd; we think he would take that as a compliment) who actually wrote a thesis paper on Survivor. (GIANT. NERD.) He first appeared on the show back in 2011, and crashed out halfway through after making an obvious strategic mistake.
Why would anyone want to go on Survivor twice? Well, if you don't succeed... Cochran became such a favorite, he was asked to return three seasons later. This time, he dominated the game, becoming the second ever Jew to win Survivor (after previously-profiled Ethan Zohn).
Why would anyone want to go on Survivor three times? You must be a glutton for punishment (or a MASSIVE attention hog). Cochran has made it clear: he is done. Even "superfans" have their limits.