Good question, Liza! I think it is a question that we will have to keep asking ourselves throughout our lives. One moment in our lifetime, we can feel very satisified, having accomplished a goal or at a total bliss lying down at a beach under the beautiful sun, or whatever it can be. Then we keep setting new goals for ourselves. Maybe some people are satisified and don't need to set new goals. For me, I keep setting new goals for myself to keep myself going.
My old goal was to pay off all of my debt, and by jove, I did it! Whoo hoo! It felt great. Now, I have two new goals that I am struggling with at the moment. That is to exercise regularly and to save more money for rainy day. It's good to keep myself challenged, but I often find myself having hard time focusing on one or two goals, but rather than multiple-tasking among different goals.
However, in my management training class at my work, they talked about making priorities, and trying to "label" our tasks as "A", "B" and "C." C tasks are small tasks such as answering emails and so on, and A taskes are major things you need to tackle on. B is in the middle. They said to focus on A tasks first and to get it over with, then we can find time to do C tasks. I'm trying to apply that to my life outside work, and have found the time to sit down and read books that I have been wanting to. It's a great feeling.
Overall, I am more or less satisified with life, but I think I thrive on challenging myself and keeping going with that.