I have a younger sister (15) and brother (13) and I literally feel nothing for them. I'm much older (29) and I left home at 18 so they are just people that I see occaisionally. I neither like or dislike them and when I talk to them I feel like we have nothing to talk about. DP says they're my family and so I should care for them but when I think about it if I didn't see them again it wouldn't make any difference to my life.