Couldn't you argue that the minute he got amnesia, the "real" Geralt ceased to exist? That was the moment the new Geralt was born. When he got his memory back he didn't lose the new memories post-amnesia. The Geralt we control in W3 is a combination of the two. While it is true that "real" Geralt's true love is Yennefer, it is also true that "new" Geralt's true love is Triss. That is why we are given the choice in the first place - the current Geralt clearly has unreconciled feelings for both of them.
Yeah i see it as the amnesia gave Geralt the chance to form an opinion on being in love with Triss in a space, without imprint of the Yen romance getting in the way. Think there's a line in W3 on Skellige where Geralt says 'couldn't you be nicer.", Yen's response 'is no, then i wouldn't be who you fell in love with."
That line felt very meaningful for me as my Geralt was trying to work his way through confused fact that even as he started to get his memories back in TW2 he very much felt in love with Triss. Then he gets a flood of paper memories showing him the extent of his history with Yen, which makes him think he has to find her and see if seeing her makes the memories come to life. Yet when new geralt meets her and is with her, he's now judging her by what made him fall in love with Triss.
As for the wish, it felt like freeing Geralt of the last fetter. I think writers wanted to use it as means of helping new players define relationship with Yen in clear branch. What the wish was, what twisted version the djinn implemented is never made clear. I would have preferred to be able to explain it wasn't just the lack of wish that meant the 'magic was dead' but also feelings for Triss. Beforehand there were people saying Geralt couldn't love Triss because of the wish, now there's people saying wish isn't what bound Geralt to Yen.
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He DID decide which path of life Geralt walks.
His Geralt is DEAD.
So, we're kind of stuck with multiple choices if we want otherwise.
CD Red's Geralt has been profoundly affected by 3 games and his death/resurrection. If he's unchanged and static, I don't think he'd be that true to the books either.
I dislike the view some people have of Geralt as a fixed unchanging character. If Geralt was this fixed character there would be no quest choices, let alone romance ones. My Geralt is a creation of CD Projekt Red's amnesia magic which opens up Geralt changing to a degree from the character in the books both in romance and quest wise.