Five things about Ali.
Most interesting to me: he dumped his 1960 Olympic medal when he represented the USA in the Ohio River right after he was denied entry into a whites only restaurant, consistent with his belief that America at the time did not want blacks as citizens, only as soldiers. And he was willing to make enormous sacrifices, including a substantial length of his peak athletic career, including the heavyweight champion title itself (with enormous financial loss as well), including a cush rotation during Vietnam that would have made him a black poster boy for a highly questionable war (and therefore a participant in the hype process). But he didn't. I don't know if I could have done that.
Even the gesture of dumping his medal he kept secret for years. When finally public with his story, he was criticized as having made it up for attention.