Replying to your first sentence... I think we need interests to live, you know, not to die from boredom... even thinking is an interest, you know. What do you mean by relationship? Admittedly, I'm a pretty boring guy, but I can manage several kinds of relationships (family, friends). Sure, you probably won't have any great discussions if you do absolutely nothing in life, but you can always try picking up a new game or reading a book or something, or talk about your memories, or the news...
And to the rest... I don't think that we necessarily need an interest in life to be interested in those things in our lives, but it certainly helps. I can't understand what you're trying to ask because there's a few big jumps between ideas in your post. Could you maybe word it a bit differently?
Post edited on 18th May 2012, 7:22pm