Update (January 22, 2017, 9:41 A.M.:) Trump tweeted Sunday morning about his inauguration’s TV ratings, rounding the number up to 31 million (from 30.6) and crowing that he got 11 million viewers than Barack Obama did at his second inauguration in 2013. This is true, though he failed to acknowledge that Obama got 7.2 million more viewers than Trump did in 2009, during his own first inauguration—perhaps a more fair point of comparison. (Trump also garnered fewer viewers than both Jimmy Carter and Ronald Reagan.)

Update (January 21, 2017, 7:52 P.M.:) The numbers are in: according to Nielsen, Donald Trump’s inauguration drew 30.6 million total viewers across 12 news networks—19 percent fewer than Barack Obama drew in 2009, when 37.8 million tuned in to watch the 44th president’s first swearing-in. Trump has not yet publicly commented about these ratings—“yet” being the operative word.

The original story continues below.

At the entrance to Mar-a-Lago, a framed printout of a TV Guide ratings chart decorates the wall, showing The Apprentice at No. 1. It’s an old chart, citing just one episode’s performance—the Donald Trump–hosted reality show was the seventh-most-watched program on television in its first year, but didn’t even crack the Top 10 in subsequent seasons. But don’t try to tell the president-elect that. In 2015, Trump earned “muffled laughs” from a room filled with TV reporters and critics when he claimed that The Celebrity Apprentice was still the No. 1 show on television. Informed that, in fact, his show had lost to Mike & Molly in ratings for two straight weeks, Trump shrugged and used a familiar cop-out: “That’s just what I had heard.”

Having ascended from the Apprentice boardroom to the world’s most famous office, Donald Trump still can’t shake his ratings obsession. Whether he’s targeting Megyn Kelly, Rosie O’Donnell, or even a golf course, our president-elect has a knack for finding the ratings angle in anything, using it as a cudgel against his enemies (“low ratings CNN) and a reward for his friends. Even now that his ratings are coming from public-approval ratings polls rather than Nielsen, Trump remains deeply invested. In the face of his dire approval ratings—historically low for an incoming president—Trump tweeted Tuesday that the numbers were “rigged,” just like the “phony election polls.” There’s as little evidence for rigged polls as there was for Celebrity Apprentice being No. 1 in 2015—but Trump has never let the actual numbers get in the way of his obsession with them.

Before The Apprentice premiered in 2004, Trump was completely ignorant about how TV ratings worked, early Apprentice publicity manager Jim Dowd told PBS’s Frontline in September. (Dowd died shortly after the interview.) But as he worked on the show, Dowd said Trump “quickly became obsessed.”

“He knew nothing about Nielsen ratings,” Dowd said. “Within a week, he started to really study up. When he studies up on something that involves numbers and entertainment, then he’s going to really kind of let that sink in. And we’d have calls every single day after [a show aired], he’d usually start calling at eight in the morning, but the ratings don’t come in until 10. I’d always have to tell him, ‘Mr. Trump, we have to wait until 10. As soon as they come in, I will call you.’ ”

The first season of The Apprentice was an undisputed ratings smash: it averaged 21 million viewers and soon garnered a two-season renewal from NBC. Dowd recalled being in Trump’s office as the official series premiere ratings came in, revealing that 18 million viewers had tuned in to their first episode.

“You could see the brightness in his eyes and his face,” Dowd told Frontline. “There was a lot of relief, to be honest, because there was a lot of pressure on him and performing and all that. He just took a deep breath, he ordered some meatloaf, which he loves, from the Trump Grill, and we all started to talk.”

As tends to happen with any TV franchise, the show’s numbers naturally declined as the years wore on—but Trump never quite got that memo, as his 2015 claim for The Celebrity Apprentice’s high ratings proved. (That also made it easier to put all the blame on Arnold Schwarzenegger when the current iteration of the series debuted to dismal numbers.) Wherever Trump’s deluded perception of The Apprentice’s primacy came from, NBC did little to disabuse him of it, according to Dowd. The publicist recalled that it became “really difficult” to reconcile the show’s actual ratings with Trump’s narrative.

“There’s about 10 people who cover ratings in terms of the publications that matter most,” Dowd told Frontline. “And he would want to make sure I called all those 10 people and told them, ‘Number one show on television, won its time slot,’ and I’m looking at the numbers and at that point, say, Season 5, for example, we were No. 72. I can’t tell that to him. I can’t say that. Maybe I should have, maybe I should have gotten [former NBCUniversal president and C.E.O.] Jeff Zucker involved, but he became kind of a monster when it came to these ratings.”

So why are ratings still such a big deal to Trump? As Jacob Brogan observed in Slate during the campaign, Trump is more of a numbers guy than a words guy—and ratings are just one more metric against which he can measure himself and others. “He’s always talking numbers, one way or another,” Brogan wrote. “During one recent campaign stop, he counted up every reference that Hillary Clinton made to him in her Democratic National Convention address—22 in all. He also routinely talks polling data—mostly when the numbers are in his favor, but sometimes even when they’re not. But no single metric matters more to him than television ratings—so much so that even polls are secondary for him. ”

In the case of The Apprentice, this could explain why Trump—the king of self aggrandizement—seems unwilling to accept any narrative in which he doesn’t come out on top. Winning the presidency wasn’t enough for him—he must have won it by a landslide, even if he actually didn’t. Trump can’t just hold an inauguration—that inauguration must be the biggest one in history, one that’s rendered stores across Washington bereft of formalwear and hotels full to the brim. It seems that in Trump’s eyes, as long as he is on a show, it is No. 1—and he must be the reason why.

The irony in all this? Nielsen ratings, like polls, are subject to flaws of their own. They only gather data from traditional cable subscribers—so as streaming platforms proliferate and more and more viewers cut the cord, Nielsen ratings numbers grow more and more obsolete and out of touch with a certain growing subgroup of the American population.

However hypocritical or illogical Trump’s fixation on ratings is, it’s something opponents might want to keep in mind throughout his presidency—just as reporters must find ways to cover his false statements without inadvertently corroborating them for readers who don’t read past the headline. Citizens looking to hit Trump where it hurts may want to start by not watching his inauguration in the first place, since tuning in will only contribute to viewership numbers Trump will likely use as an objective sign of America’s infatuation with him. True, the inauguration ratings won’t discern who was watching and who was hate-watching—but neither will Trump.