Seems to me that the runaway son was looking for love, a sense of significance and, dare I say, fun? He exhausted himself and his resources without finding lasting satisfaction. Until he returned to his Father's house, that is.
The older brother never left, but seemed to have the same hunger. He was existing right in the middle of all that he craved, but he was living like he still needed to earn it. It was his Father's desire for him to know he was loved and significant. His Father longed to for him to enjoy their relationship, to live in joyful celebration.
Many live like one or the other of these boys. Some are in constant pursuit of pleasure and significance from the stuff of this world. It's an insatiable hunger that never gets satisfied. Others sit in their Father's house never knowing that all He has is already theirs--they don't need to earn it. They are hollow-eyed with hunger as they sit in the presence of plenty
It's when you know that you are the beloved, treasured child of your Father that you find significance and contentment. We need to stayed tucked in close to Him to keep that awareness fresh in our minds...otherwise, we seem to wander and begin to search for it elsewhere. When we really know it we're not so quite so devastated when others don't recognized how lovable and significant we are. When we really know it life becomes fun.
Look into His face and you will see that you are loved--no matter what you may have done or not done. You can't earn it, and you can't lose it.
The Lord your God is with you;
His power gives you victory.
The Lord will take delight in you,
and in his love he will give you new life.
He will sing and be joyful over you...
You can find the whole story of the two sons in Luke 15:11-31.