Can I change who I am?

Can I just decide to be a person who is not sad when a good thing ends? I want to be a person who is happy something happened rather than sad it ended. It’s easy with small things – I don’t cry when a good movie is over or a good meal ends. I’m glad to have experienced it. But its tougher with seemingly “bigger” things. Is it just an observation that in the past I’ve tended to get sad when good things end, and I can choose how I want to be in the future? It feels bigger than that – like I’m trying to go against my natural way of being, but maybe that’s just drama? Thanks as always <3