"You can say anything with a Post-It. I’m not entirely sure why that is. Maybe the friendliness of the squares makes it easier. A square is nicely compact and less intimidating than a full page. And they come in cheerful colors. Non-white paper is kind of inherently festive. Or maybe paper that sticks feels more important than paper that can blow away. (Though you can move them, if you need to put them somewhere else.) They might not be as lasting as words carved in stone, but Post-It thoughts will stay. For awhile, at least."