What does it mean to know who I am?

In movies whenever people are describing who they are it’s always “My name’s Jimmy. I like pizza and hate salad. I work at a chocolate shop and drive a truck. I am married to Laura. I live in a small house in a huge neighborhood in Seattle. I don’t like winter because it makes my fingers cold and I don’t like summer because it’s too hot to do anything. My favorite color’s red.” Something like that. Is really, really knowing who you are just knowing your like/dislikes, favorite things, address, family, etc. etc. etc. things you can tell other people easily? Or is it something deeper? And how do you know who you are in Christ? This has been bugging me a whole lot lately and was wondering if any of you could help.