I knew a doctor who couldn’t get into medical school in the states, so he went to Italy. Really nice guy, but very unsure of himself, and not the best doctor.
Pretty much the same situation with my friend. He was self-conscious about his credentials, so after a few years of general family practice, he shut down his practice and was accepted into a graduate program at a prestigious medical school here in the US and turned out to be an exceptional specialist in his field.