I wrote my first book in long hand and then typed it out on this old iMac that I loved. And I did research how to format the book and all those little things I needed to do so an editor or agent wouldn't throw it in the trash when they first looked at it.
That first book was a romance and I read all the books and attended a conference where I learned some basic expectations of a publishers. One 'rule of thumb' was that each chapter should be twenty pages long. As a lover of fantasy novels, I already thought the rule a little silly but it was followed rather closely in those days. I wrote my earlier romance novels in the confining style.
I'm not sure if the twenty page chapter is still recommended or not but I seldom think about it anymore. I've read a book in the past week that had a chapter on paragraph long. Some books don't have chapter numbers but titled each chapter by the name of the viewpoint character. It's so much easier to end a chapter when the action or drama calls for it, the whole hook ending, instead of sculpting the story around a page count.
Do you remember being told chapters were to be a certain length? Do you give any thought to how long you make your chapters? Do you care as a reader how long chapters are?