Imagine a boy at recess who only wants to keep the ball, never shares, never lets anyone else play. What happens? The other kids leave, he ends up alone, a fight starts. Proverbs says: the selfish always cause trouble.
Now imagine another boy who shares, includes everyone, and trusts there'll be fun for everybody. What happens? Everyone wants to be near him. He has more friends, more joy, more success. The secret isn't being clever, it's trusting God. When we know God is our source, we don't need to hold on to everything. We can share!