A little difference can cause a waves that move the world. Like when a person who is supposedly know for its impact on surrounding and others, suddenly transfer its action radius from story protagonist that spin the story wheel, to an observer who is nearly in the role of heroine. Instead of actively rushing forward it passively waiting for a next event, that will put it into a distress, waiting to be rescued by a hero.
It was nearly as if this person lost its memories and it cause such big impact of difference, that the others got into a shock. They wonder if this one dint fall into a crisis of personality, wanting to turn the book into a blank page and now pretending to have a memory lose. We shall not throw away the possibility of this gig to be some kind of game as how long it will last until someone will shatter the glass illusion. Like some game as who will freak out, back down from the challenge. A random passerby or observer can imagine a mind games battle as one can think ("I hope they will not find out!") and the others with red glowing eyes ("Yea~a, we know!").
Or they are like ("Not a chance! I will not be the one!") and not just breaking the illusion; they dint tell this person anything about its past, not true or lies, letting the former protagonist in dark. So it cant have a solid foundation to build on.
Normally one will think, that in group of bounded friends who don't bother to honey the facts, if someone meet this state: someone… someone will slap them mercilessly with facts and acts, in order to wake them from memory loose. ("Slap! Slap! Slap! Wake up!")
There is still the chance of a (honest?) approach to desiring a new start, to throw everything behind and move on. But tho throw the rest of the party out of rhythm by this? Maybe they are honest, not to spoil the new beginning by pouring old memories.
O~or… And hear me out! They are determined, they waiting for the protagonist, to wake up from its wonderful dream. So they will be there, to observe, to see the reaction, as the former personality will face-palm itself, about how silly, how out of character the owner of that body was, while the true protagonist was sleeping. So the friends can laugh into its face, as it will dying inside from shame.
Anyway, the gang did ask ("Are you serious?!") with confused expression as one by one meet the new personality. Or all of them acted according to certain plan. And try to guess: Who's plan it was?