I had an unusual situation with a friend who offered me a great deal of goodwill but who would accept none in return. She helped me through some very difficult situations and was always available to talk. Every time I tried to return the favor, she declined.

I finally realized she was using me, and several other of our mutual friends who were also going through a series of personal problems. Her life was a mess, so I think she surrounded herself with people with serious difficulties to distract from her own. When things improved for us, she lost interest.