A Children's Book

I appear to have lost myself. Where could I be? Have you seen me?

I look for myself in some books on Greek mythology. I am not there.

I look for myself in a bottle of Moscato. At the bottom lies something that feels a little like me, but it is not me. I am not there.

I look for myself inside someone I love. Is that me? No, I am not there.

Where am I?