Charles darwin did poorly in school as a young boy. how did his poor performance belie his genius?

Charles Darwin always had a taste for natural history as a kid, as far back as eight, in spite of how he performed in school. When he was a young adult, he got an apprentice ship as a doctor from his father who was also a doctor. This gave him experience with the anatomy of the human body. When being a doctor started to bore him, he learned taxidermy, exposing him to the anatomy of wild animals. Later he joined the Plinian Society which was a student natural history group that often debated and questioned the current topics and views of the subject in that time. Not too mention the many natural historians and evolutionists who also inspired him, one of which was his own grandfather,that gave him the support he needed. I guess that even though his normal school curriculum did not interest him, his self determination was enough to keep him grounded to his interests, proving that sometimes a great education doesn't always make you a genius. (idk :) Charles Darwin was smart in his own ways.