I remember reading a psychologist commenting on that. Most view the future, as in 50 years from now, negatively because chances are the person will not be in it. I don't know how true that is! but thought it potentially interesting.
Having done my family tree, I've come to learn that little of a persons life tends to be remembered. Sometimes though short biographies will be written about a person and family. Other times a person will write a life long diary, which is kept and passed down though the family or even turned over to a historical facility. The LDS church has all kinds of detailed records on peoples lives. I've always found those fascinating.