Why do I need to tell people good news?

I’m divorced and both my parents are deceased. When I have something truly amazing happen (like an award or some other big win etc) I feel a need to tell someone, but the normal people I’d brag to are gone. I know I can tell my friends and my sister, but I’d like to be the kind of person who doesn’t need to. I tell them and they say nice things but it still feels a little empty at the end. If I don’t tell anyone at all, it almost feels as if it hasn’t happened. Why do I need outside validation and how do I get to the point that I feel good enough about it on my own without telling anyone?