Helping others

Yesterday was a fun day hanging out with Kathy. She needed me to take her to town since she can't drive for fear of having a seizure. I enjoy doing it and it makes me wonder why I or anyone feels good about doing stuff for others. Is it because we sincerely want to help someone? Or is it mostly selfish, because it makes us feel good about ourselves? Or a combination of both? I have a friend who used to suffer daily pain. He laid around all day feeling sorry for himself. He decided instead of sitting around he was going to help someone every day. He says since then he hasn't had that pain. His truck says on the front, "help someone today". He and I are going to do a plumbing job for his daughter on Monday. I'd do anything for him because he'd do anything for me. Do most people have a friend like that?