I think that there is a direct correlation between the 2 things. The most successful people that I know seem to be the happiest! Now I am not saying that they are happy with all aspects of their lives at any given time, but they do have the means to influence and/or change their “happiness quotient” based on what they do and who they are!
I also believe that being happy with who you are and what you do will undoubtedly make you successful. If not in the worlds eyes but in your own eyes and that success will breed passion and enthusiasm which will draw others to you and they will believe that you are successful and will want what you have. It is a cycle that I think we should all strive for.
Go find something you love to do, and then put your heart and soul into doing it. It won’t feel like work which will make you want to do more of it, and because of that you can’t help but be successful.
I am a luck guy as I love what I do and can’t imagine doing anything else. I do believe that there is something out there for everyone, where they could give the same answer if asked the questions ” What do you do ? Do you enjoy or love doing it ?)