Today marks the 65th birthday of a legend: Muhammad Ali. The self-proclaimed "greatest of all time" boxing champ has withstood the test of time, leaving behind a legacy of sporting dominance, and more importantly, cultural change. But what was the secret to Ali's success: his superb ringmanship and boxing skills, his grandiosity and bravado, or perhaps something longer lasting - his authenticity?

While many today remember Ali as a great boxer, and others note his importance in urban culture (including being a forefather of the rap genre), Ali most notably shook the world with his opinions on society. At a time when African-American athletes were discouraged from expressing themselves too loudly, Ali brashly shouted his true feelings on a wide variety of topics, earning him both notoriety and unconditional support. Whether changing his name from Cassius Clay to Muhammad Ali, and in the process introducing many white Americans to the Nation of Islam, or refusing to enter the draft for the Vietnam war, Ali stood up for what he believed in, regardless of the penalty.

Muhammad Ali's importance extends beyond the boxing ring, as he created a forum where athletes could express, and influence, public opinion. However, unlike the multimillionaire athletes of today, Ali's actions and words were not motivated by monetary gains (in fact, Ali's actions often cost him money and nearly ended with him in jail). It is the simple truth, the authentic beliefs and feelings that Ali expressed that reverberated with Americans then, and still echo in his shadow now. Ali's lasting legacy will be his willingness to be himself, and will forever let him retain the mantle of "The Greatest."