Anatomic variations can account for a Nolan Ryan, who could throw a baseball faster in his 40s than most pro pitchers in their prime. You don't want to get medical help from a person who has a textbook mentality. They may do you a lot of harm. That may be true for most people, but a few people have their appendix elsewhere. Now back to creativity.
Textbooks usually present the muscular system as if all the skeletal muscles have been discovered.
These were not tiny muscles either. These new muscles, labelled sphenomandibularis, actually help us masticate. Chew to you. Their discovery shocked the anatomy community. One explanation has to do with the ways dissections are usually done.