In Terry Pratchett's Tiffany series, witches can "borrow" animals bodies. Tiffany borrows a bird, and flies away, until she forgets how to talk, how to think like a human, that she even were human.

Today I was thinking about who am I and I remembered, gee, I wasn't always an half failure of a university student, I was travelling, I was a farmer, I was a juggler, I was... so many lives that it amazes me how can I forget about every single one of them.

Not sure if I'm losing a treasure or I am letting go of a burden, by forgetting them