Probably the biggest purpose for me is to have something to look back on. The last time I consistently journaled before this was during the time when I dated, got engaged to, and married my wife. Granted, that was more than a line journal, but it has been really nice for us to go back and read it together all this time later. With the line journal it is more of a prompt to help me remember that time period than a detailed description. But also I guess there is an autobiographical aspect to it that appeals to me--maybe someday I'll use it to help write an actual autobiography. And if not I also like to think of it as something to leave for my kids or grandkids to read when I'm gone.