Why is it that other people's lives seem more interesting than our own? Maybe (probably) they aren't more interesting, they are just different. We're used to our own story, we've lived it. But others haven't. What you've done, where you've lived, what you've experienced - it's interesting!
A personal history is a way to capture your unique story and share it with those who come after you. Those who are interested and may never have the chance to hear it from you in person.
I was interviewing a gentleman the other day and in the course of describing his childhood home, he mentioned that they had an outhouse. And they had to move the location of it every so often because it would fill up. What? An outhouse?! This might have been common then but it cerainly isn't now. This man experienced so many changes over his fascinating life. He had this wonderful firsthand account of things (we take for granted), becoming a part of our daily lives - indoor plumbing, home telephones, television.
Because you've lived, you've experienced. Because you've experienced, you've learned. And what you've learned has brought you wisdom. Save it. Share it.