Why do people continue to work after they have achieved their financial goals? Because it makes them happy! When you do what you love, your brain releases endorphins that make you feel good and gives you a natural high.
Happiness is the progressive realization of a worthy ideal. When you are moving towards a goal, your brain motivates you by producing more endorphins. So if you are loving what you do, it makes striving for achievement motivating and it is a forgone conclusion you will become successful ..and have fun doing it!
I hope you are doing what you love.