What does it mean to have an empty life?

I have plenty to be happy about.

I have much for which to be thankful.

I have great friends. I have a wonderful family.

I have known both love and heartbreak.

I have experienced joy, anger, sadness, fear, boredom and laughter.

I have accomplished and I have failed.

I have learned much and look forward to learning much more.

I have known both arrogant certainty and intense doubt.

What am I missing?