There is a thread in housekeeping which will explain it better than I will but basically it's using a normal notebook as a diary/planner/life changer.
You set it up to suit yourself so no restrictions on layout. You can also put additional pages in to keep track of other things. I have weight loss, grown up stuff, gift ideas.
You have an index at the front so you just put stuff in as it happens and don't need to leave any blank pages.