At the simplest level, success is knowing what you want and then achieving it.
Using this definition, we can have success from achieving short term goals as well as long term goals. In fact, long term success often depends on achieving many short term goals. Therefore, success and feeling of success tend to feed on themselves!
I love your definition also, it's really straight to the point.
I really thought about success and what it means. The one I spoke about makes it much simpler