You spend your whole life inside a body you can only see partially without assistance.

You have lived your whole life inside a body you have never fully seen. Your own back, the top of your head, your face in motion. It takes mirrors, cameras, and other people to assemble even a partial picture, and the assembly is never quite complete.

There is a kind of ease available in that. You are not the manager of an object you can inspect, you are living inside something. If you are inclined to be harsh about how you look, it might help to remember you have never once seen the thing you are being harsh about.