Once upon a time there was a very clever man. He knew lots of things about lots of things and he could do lots of things and fix lots of things. This man liked to help his friends and family when they had broken things or were stranded with some emergency. He gave his services for free or at least for cheap. He became well known among his friends and family as a man who could be a very helpful problem solver. Very useful. Yes, very useful, indeed.
Then one day he began to notice that no one every talked to him except when they had a problem. He noticed they never called to chat or asked how he was. They never suggested he join them for dinner and a movie. The man began to wonder if his usefulness was the only reason people liked him. He wondered if anyone liked him because he was kind, or nice, or just because they should. He began to wonder if they liked him only because he fixed things for cheap or rescued people from emergencies.
So then he had to decide: was he being useful or was he being used?