Consider a hammer. It's designed to hit nails. That's what it was created to do. Now imagine that the hammer never gets used. It just sits in the toolbox. The hammer doesn't care.
But now imagine that same hammer with a soul, a self-consciousness. Days and days go by with him remaining in the toolbox. He feels funny inside, but he's not sure exactly why. Something is missing, but he doesn't know what it is.
Then one day someone pulls him out of the toolbox and uses him to break some branches for the fireplace. The hammer is exhilarated. Being held, being wielded, hitting the branches -- the hammer loves it. At the end of the day, though, he is still unfulfilled. Hitting the branches was fun, but it wasn't enough. Something is still missing.
In the days that follow, he's used often. He reshapes a hubcap, blasts through some sheet rock, knocks a table leg back into place. Still, he's left unfulfilled. So he longs for more action. He wants to be used as much as possible to knock things around, to break things, to blast things, to dent things. He figures that he just hasn't had enough of these events to satisfy him. More of the same, he believes, is the solution to his lack of fulfillment.
Then one day someone uses him on a nail. Suddenly, the lights come on in his hammer soul. He now understands what he was truly designed for. He was meant to hit nails. All the other things he hit pale in comparison. Now he knows what his hammer soul was searching for all along.
Same goes true for our purpose in life -- we may do 'many' things, or we may get much 'more' to satisfy our never ending desires, but in the end, it is only the real purpose of life that results in fulfillment.