HISTORY. Geography. Money. Politics. Law. Persecution. Racism. Psychology.
Even Manchester United, Harrods and the price of high-speed sports cars.
Mike Tyson's big-fight build-up has touched upon all those matters and dozens more at a torrential rate of thousands of words per day for nearly two weeks now.
But until yesterday, there was one subject upon which he had muttered little more than a few reluctant and token lines in public. You know...don't you. Yes, boxing.
Finally, as the circus at last stopped performing and the business of punching and hurting Julius Francis loomed seriously into view just 48 hours away, Tyson revealed his game plan.
It surprised no-one, but still it claimed the attention of everyone in the way only Tyson can as he said: "I'm here for war. I am an animal in the ring.
"I am a ferocious fighter. That's what I am. You can't change it. I never doubt it.
"And when I say animal, that is the best word to describe my approach to any fight. I will fight by the Queensberry rules, but I am going to blaze."
When Tyson talks like that, he usually means it. Which is why people's ears prick up.
Yet beside him sat Francis, clad in dark glasses and oblivious to Tyson's words because of the headphones he wore, blasting American rap music.
At one stage, it seemed nobody was going to hear Tyson speak.
He was fed up with being mobbed, fed up with the media zoo that follows his every move, fed up with the questions, we were told by Tyson's people. He might not show.
Even that, of course, would have been a major story. But eventually he turned up at the 21,000-capacity fight venue - the MEN Arena - for his first face-to-face meeting with Francis, the British champion from Woolwich regarded as a complete no-hoper in the 10-round bout.
Suddenly, the boredom and frustration that comes with knowing that the fight really is now just around the corner, surfaced in Tyson.
He said: "Fighting Julius Francis is the only thing that concerns me now. Perhaps we can have fun after, but right now I have to work. I am in great shape and I look forward to being victorious. I just can't wait to go."
That, I'm afraid, is the full extent of what Tyson is prepared to let us know of his thoughts about the fight.
Perhaps that is because he too considers Francis a no-hoper and he can't think of anything else to say about him.
At least he didn't feign sleep as he has done at many of these set-piece occasions in the past. "Everybody's talking but I've got to get into the ring," was another signpost of Tyson's impatience with the build-up and desire just to get it on. …