Great message, but "self-made" never meant someone who became successful with no outside help. One is self-made if their fortune wasn't inherited, that's it.
To those down-voting me: Firstly, I would invite you to consult a good dictionary. Secondly, I'd invite you to undertake a moment's reflection, which I believe should make readily apparent the utter uselessness of a word that describes not a single person that ever lived.
But they also know that Arnold is using artistic licence in pursuit of his objective, which is to convey the importance of having humility and gratitude as you seek to achieve success.
The people downvoting you, I'm quite sure, are doing so because you've perhaps come over as unnecessarily pedantic, given the spirit of this message.