If you are using a smart phone, have a Google or Facebook account, an email account, spend electronic money, or take photos then you already ARE logging your life. I am constantly amazed (and occasionally grateful) that there is such a comprehensive log of everything I do from credit card expenses and receipts, to Google/Apple map history, to EXIF photo (location) data, to social network interactions, to email and texting information. I compile much of that information into a MySQL database to get a better timeline of my history.