Choose to be happy?

I’m all about mental strength and your thoughts create your reality. So what do you guys think about choosing to be happy and content with what you have vs knowing your worth and feeling you can do better.

I feel like these are both valid points of view so what are your thoughts? How do you maintain happiness and contentment when feeling you can maybe do better?

*edit referring to the home you have for your children, the relationships you surround yourself with, your job; things along this line not referring to self development but life surroundings and situations*