For future reference!
That pain chart isn’t a very good reference. My mother (who is a tattooist herself) has a tribal piece she slept through and it was done on her temple. A good reference is this: if you’re ticklish or sensitive in an area, you will find that it will be more painful. It’s about clusters of nerves, not closeness to bone or any of that. But the text is correct ribs, feet and spines, yup! those hurt.