What do you use your sketchbook for?

Personally, I have two main sketchbooks one is 9x12 and 14x17. As an artist you need a sketchbook because it keeps you organize. And yes, you can draw on regular white copy paper, but it's hard to keep them all together in order in folder. With sketchbook, I always put the date on the first page drawn, then the last page. And I wrote "From Month/Year to Month/Year on the cover. The reason I