No, they EVOLVED.
I think of it like caterpillars. Do you grieve for the caterpillar when it becomes a butterfly?
I'm evolving, i'm growing up but i'll always be ME. What's inside me doesn't change (except perhaps i'll be less miserable) it's just the shell.
I will still be the same person, just a happier, healthier form of me. A more genuine and honest one.
I'm not dying, i'm just making some adjustments to the meat suit my conciousness is stuffed into, to make it more comfortable to wear.