I am a busy person, and I could never find the right type of calendar, app, or "to do" list that encompasses all my roles: employee, business owner, volunteer, home owner, pet "owner" (really, they own me), mom, etc. So I designed my own book, small enough to keep in a computer bag, purse, backpack, or car, and with all the categories I need, plus some extras that others might need. I use Post-It Notes or similar type separators for the sections I use the most, such as "Pets To Do List," or "Online Shopping To Do List." Then I can easily flip to that section to fill it in and check it off when done. But you can also use the Table of Contents, and each "To Do List" section has its own headers to help you know you are on the correct list. As well as 27 To Do lists by topic, I have added, at the end, at Password Hints section, a Personal Phone List section, and a year's worth of fillable calendars. I have added a "Priority" space to the right of each line; you can use or not. If you use it, some prefer the A through F grading system, while others use numbers 1 (do now ) through 3 or 5.