Dear reader, I have been thinking. No, do not worry, please. It did not hurt. Not much anyway.
Some time ago I gave some thought to the time I spent on the average chapter of the last three books I wrote. With that I mean the actual first writing, then the reading of it to see if it makes some sense, the rewriting of parts of it to make it better, and then the final nitpicking on making it as error-free as authorly possible. To this I should add the time that two people help me in making sure the story flows along, and the offences against the English language that I involuntarily add is removed again. I did, however, not do that.
When I added all that up, dear reader, I came to an amount of somewhere between 4 and 5 hours per chapter. The actual time of course depends on the length of it, but 4 hours is the least I spend on a proper chapter.
Then I thought “My goodness, considering that the latest 3 books are all over 40 chapters long… that makes for a lot of hours!”
3 books, at least 40 chapters, each chapter 4 hours or more. That comes to at least 480 hours, a minimum of 160 hours per book. And that only comprises the work on the text. No time counted for research, looking up various things, and work on the cover, or turning the chapters into a proper ebook.
Those numbers surprised me. A lot.