Can I just say that Rafiki is probably my favorite Disney character of all time. He is literally crazy but the wisest out of everyone in Lion King. And we all know that the crazy characters hold the deep messages. For example Frozen. Olaf anyone?
Rafiki, acted as simba's really world representation of his superego. By pushing him to return to the pride lands during a time in which he was indulging in id satisfying behavior as an out cast with timone and puma.