I had a surprising experience with a 10 year old child "Carl" a few years back. He had all the stereotypical signals of a gifted kid that can be drilled into anyone by a dedicated parent- 1500 chess elo, constantly pestered me about the research I did during the semester, used big words, etc. This was pretty common at the camp. However, he just felt different to talk to- felt sharp. He made a serious but failed effort to acquire my linear algebra knowledge in the week and a half he was there.
Anyways, we were out in the woods, a relatively new environment for him. Within an hour of arriving, he saw other kids fishing, and decided he wanted to fish too. Instead of discussing this desire with anyone or acquiring a rod, he crouched down at the edge of the pond and just watched the fishes. He noticed one with only one eye, approached it from the side with no vision, grabbed it, and proudly presented it to the counselor in charge of fishing.
Until this incident I was basically sceptical that you could dump some Artemis-Fowl-figure into a new environment and watch them big-brain their way into solving arbitrary problems. Now I'm not sure.
His out-of the box problem solving rapidly shifted from winning camper-fish conflicts to winning camper-camper conflicts, and he became uncontrollable. I almost won by breaking down the claim "You have to do what I say" into "You want to stay at camp, here's the conditions where that happens, map it out- you can see that you're close to the limit of rules broken where you still get what you want." This bought two more days of control. Unfortunately, he seems to have interpreted this new system as "win untracably," and then was traced trying to poison another camper by exploiting their allergy. He's one of two campers out of several thousand I worked with that we had to send home early for behavior issues.
In the end, he was much less happy than the other campers I've had, but I also think he's one of the few that could survive "Hatchet" or "Call of the Wild" style- despite comparative lack of experience.
Addendum: he harassed and kept catching the poor half-blind fish for the duration of the stay, likely because he got so much positive attention the first time he caught it.
Oh my, I hope your sanity is holding.
In a sort of morbid way, seems like things are working as intended - the "sharp" fella is winning social battles (invented or not) and keep exploiting the ever widening strategy space. Emboldened, he quickly gets to the "this is the line and no further" boundary of his current strategy. But instead of modifying it and keep his old strategy as a tool in his arsenal, he over-exploit it and disrupts the equilibrium so much he gets kicked out.
I fear that happiness may be a sort of consolation prize in the games we're talking about. If we agree that the factor we're talking about is mutually exclusive with happiness, then we can describe him as someone who may have considered the full portfolio of benefits of both option and chosen the one that's not available to most "normal" people.