OKAY SO Changeling has this "Banality" mechanic where your morality gauge is really your magic/belief gauge. Banality is low in children overall and then blah blah World of Darkness sucks so you lose the ability to believe in magic when faced with things like taxes. Changelings are Changelings rather than true fae because being half-mortal is the only way to survive. A Changeling exposed to large amounts of Banality essentially loses their Changeling nature and becomes fully mortal, losing all memories of their fae life. However, an infusion of enough Glamour can reawaken the fae soul and bring the Changeling back.

This has definitely happened to Even in the past.

He's...back, somehow, but he's really careful these days about keeping his Banality low and his Glamour high (often skirting dangerously close to Bedlam, aka "wow too much Dreaming not good for you"), avoiding combat especially with chimerical weapons, and so on. He preferentially hangs out with all these other nonhumans, because while their Banality is variable, it tends to be lower than that of mortals.