I love the detective work of finding out about my forebears. I'm fascinated by their lives without electricity, indoor plumbing, hospitals, cellphones! How did they do it? What kind of people were they, and what were they concerned about?
When I find a birth certificate, death certificate or census record, the usual sources of historical clues about individuals, it's a small treasure, but tells me little of their actual stories. A rare find is a newspaper or book article. There once was a long newspaper article about a great grandmother and all she did for her church. It was stuck in the inside cover of her family Bible. It's not there now; my mother "cleaned it out." -sigh-
Why this fascination for family history? I think because they are my family and they always will be. They don't change or go away. Also, many of their struggles are the same as ours, loss of a loved one, marital discord, financial downturns. How did they deal with them?
In the Bible God warned against pursuing "endless genealogies," and they are endless! They double with every generation back! But I think the problem was the temptation for people to rate themselves based on who their ancestors were. ("I'm purer bred than you are," or "I'm descended from kings.") God wants us to realize that our importance is based not on our relationship to people before us, but on our relationship to Him.