The limbo
It's that feeling of not belonging anymore.
You come back and you're a completely new, different person; you feel the same but everything has irremediably changed and your puzzle piece just doesn't fit anymore in that big picture.
You belong to a different reality, a different set of pieces.
And it's sad, because it's where you grew up, where you used to belong.
You feel stuck in this limbo made of memories and new feelings and you don't know what to do.
So you're left with the certainty that you used to feel good there but not anymore, it's just not good enough and you taste the bittersweet reality of knowing that things will never be as they used to.