I wish more people were like you. Not many boaters are out on the water enough to stay up on even the basics so an annual review of the rules,
lights, nav aids etc is an excellent idea (I did a few of the flash cards and it comes back to you, but I had to think for a few minutes on some of them) . I home studied for the exam, and passed, but I think I would have retained more relevant info if I had taken the class, and it wouldn't have taken me nearly as many hours as it did not knowing what to study (had to study it all). Like you, I was just doing it for my own education. Your odds of passing are statistically pretty poor doing it on your own.