On the other hand, he may have been hampered by not being hungry. Unlike many (but not all) of the successful boxers, he didn't grow up poor and without opportunity. He grew up with two good parents, middle class, had his pick of colleges to which he'd have received a free ride for track or football, could probably have played in the NFL. Imagine him, with all that athletic ability, instead growing up dirt ass poor in some inner city area, with only boxing as his route out. He'd have been a totally different dude.
That's why I said up thread that the guy had all the tools on the planet but there was just something lacking from propelling him to really true legitimate greatness. His historical rep IMO is based on the three fights with Ali, an opponent who in the grand scheme of things was 99 solar systems above him but for whatever reason he just looked arse against Norton.
In his book, he basically says he was always lazy, never trained to the fullest, trained the minimum necessary to get by on his god given athletic ability… except when he fought Ali. Ali was the one who brought it out of him, who actually made him work hard in camp. He’s pretty honest about it in an unflattering way to himself in his book, so I assume it’s the truth.