This is, it seems to me, a general principle: you get bored with something not when you have exhausted its repertoire of behavior, but when you have mapped out the limits of the space that contains its behavior.
I have cited this previously as sphexishness and piercing the veil. You don’t need to beat the game if you can see how to beat the game. At that point, it is just a series of motions. All mental activity is done, although you might enjoy the physical act of mastering the motions (more so in meatspace than “hitting the buttons in the right order”).
In MMOs, we have the grind: repeat x 5000 times to level. Many single-player games having something to be brute forced, such as perfecting the timing on a dozen jumps in a row (missing one means starting over, maybe a long run away) or randomly mixing together three potions to see what the combinations do. You might as well look up what the right combination is, because there is neither fun nor virtue in trying every combination until you get the right one.
We MMO players are probably too tied to our games. Can there really be enough content in a game to entertain you for years, not months? It is an unreasonable expectation, and we should not leave to bitterly once we have seen what all the game can do for us. The only reason you were sticking around in the end was for the people you played with or against. It is fitting that Mr. Hofstadter continues: “The behavior space of a person is just about complex enough that it can continually surprise other people…”