Balance in all things, I suppose. It seems to me now that looking for happiness in accomplishment is a bad gamble, because life is not predictable enough. You can't make success happen just by working at it; you have to be in the right place at the right time with the right idea, you have to encounter none of the many outside factors which might derail you, and it's only in hindsight that you get to find out whether you ever had any real hope of success.

Your project will probably fail, because most projects fail, so if you are deferring present happiness in order to invest in the hope of future success, you are probably going to be less happy overall. Success feels good, to be sure - but then what? Another project, which will probably fail. So I think it's important to find a way to live a happy life whether you are trying to accomplish anything or not, and then the occasional success can be a bonus when it happens.