Notice that the man in the story is already rich before the abundant crop comes in. Notice also that he already had barn enough to store the crop. But here's the problem. The harvest was so good he couldn't store it all. What to do? he asks himself. Should I give it way or sell it at the market? Neither. I will build bigger barns and keep it for myself. He is not thankful for the riches that he already has. He wants more to insure his security. He doesn't want to live for the day; he wants to live today trying to ensure the pleasures of tomorrow. We call this greed. To clutch our wealth as if it is an end in itself is the sin of the Barn Builder.

Jesus is asking the younger brother at what level will you have enough? You want too much. Be happy with what you are getting. Beware of greed.