Often times we see fulfillment as accomplishing a task or getting something done. Fulfillment is much deeper than that. It is an inner state that is not about doing but acknowledging that whatever you do you are in a state of aligned being in whatever action you are doing.
When you are guided by your aligned state you stop trying to do things to make you happy and instead allow your happy to guide you to where you can continue to share you happiness and continue to feel aligned and continue to allow your happiness to act through you