Questionable Questing

recipient of the wish being permanently happy in a drug-like haze, unable to feel any kind of other emotion apart from permanent happiness, everything brings them joy, from doing nothing, being beaten up and killing people.

I mean... other people would be horrified. But I doubt the recipient would care. And as long as it is really eternal, they never will.

There's the fact that the Nasuverse would Lostbelt your ass before you can say Quantum Timelock if everyone gets to be eternally happy, but that's not really the point.

Is it that everyone gets eternal happiness? Or just one specific person?

There is always the option of simply making it so that their brain is constantly producing the chemicals that make them happy, and is no longer capable of producing the chemicals that make them sad or depressed.

So they come home to find their love bleeding out? Internally horrified even as their face stretches into a massive grin over just how happy this makes them. They know that they should be sad, calling for help, or something, but all they can do is bask in the afterglow of this wonderful situation

Basically existential horror as they KNOW that their wish is warping whom they are as a person, but they can't do anything about it, or even work up the desire to want to change it.

Happiness could be interpreted as mania, and the recipient of the wish *could* just spend the rest of their life and afterlife manic without any *additional* energy to make that anything more than a constantly-exhausted unable-to-think hell. Like a mental version of that one WH40k daemon of Slaanesh that pissed them off, so they cursed the daemon to never stop dancing.

Eternal happiness but it's taken from loved ones

Alternatively, happiness become meaningless and turn into stagnation. If you are just happy, then you would do nothing to change your situation. You would not improve yourself nor would you truly affect the live of others. I'm not saying you need to suffer to grow, but hardships and walls ARE part of the package for that.

Another possibility would be to be trapped in a dream where everything is always perfect, with the dream rewriting every discordant feeling as soon as it emerges. Or to live life as usual, but with the wish constantly erasing any less than happy thoughts. Yet another possibility would be to be assimilated into another being that is happy but whose values are utterly alien or inimical to those of the person.

The more mundane answer would be to experience a happy life, but always knowing that every moment of joy, every triumph, is no more than the result of a wish made long ago. That your life is happy, but fake and worthless, and, ultimately, you can't even care, because your wish won't let you.

Also, it depends on what someone considers "happiness".

Like, Darkness from Konusoba would be a very bad example for someone elses 'happiness' lol.

Thanks for your thoughts.
We all go back to the same problem though: The Wish can be fulfilled in a way that could horrify us before getting it granted, but not afterwards.
After all, if the twist made us unhappy, the Wish would've failed; if it didn't, it would be because we'd lack have the capability to care about whatever consequences it had.

I guess the question is... would you ask for that wish, even knowing the risks?

Yeah, I suppose it really depend on how you write it. Like if you say peace on earth, you could do it by reducing the earth population to 1 or just mental brainwashing that no longer recognize the idea of violence or even negative emotions.

Big vague wishes from a morally dubious source are always a big NO from me.

Way too much risk of unending horror for a long shot payoff.

To borrow from Fate/Zero, I suppose it also depend on how you would see 'Eternal Happiness' happening to start with to think of how the wish would be done.

I absolutely wouldn't. Even if future me wouldn't have a problem with it, that would only be because present me would have undergone personality death.

Though that brings me to another way it could backfire, that is, by introducing several eternities: in one you experience the horrifying happiness, in the other you are just aware of everything awful that's going on with your other self. Basically, if it's only horrible to a spectator, make the character also a spectator.