Donald Trump is really rich — or, to put it in his own words, "I'm really rich." Yet sadly, Americans will be deprived of the experience of beholding the majesty contained within Trump's tax returns. Unlike Hillary Clinton and every other major party nominee in the last few decades, Trump will not be releasing his returns to the public. And not only that, I'm pretty sure he won't release them even if he becomes president of the United States.

As you know if you've been following this issue, Trump has said that he can't release his returns because he's being audited by the IRS. Like many things Trump says, this is utterly bogus: The IRS has stated that he's free to release them if he wants to, and doing so would have no effect on the outcome of the audit, because the IRS already has them. It isn't as though they're going to find out something they didn't already know.

But as James Fallows observes, given that Trump has taken criticism for not releasing his returns and will certainly take more, he must believe that whatever is in the returns will do him more damage than continuing to stonewall. Nevertheless, there is more than one kind of damage he could incur. There's damage to his presidential prospects, of course. But there's also damage to the public image, and self-image, that he spent so long constructing.

Democrats say that if Trump isn't releasing the returns then he must have something to hide, and that's almost certainly true. There are any number of suspects, including sketchy deductions, stingy charitable donations, financial chicanery of one sort or another, or an extremely low tax rate. You'll recall how much grief Mitt Romney got when it was revealed that he paid a lower rate than most Americans who work for a living. Trump certainly does; he has cited Romney's experience ("He might have lost the election over that") as one reason he won't release his own.

There would also probably be enough material in the returns to keep a battalion of opposition researchers busy for months untangling the web of Trump's business relationships. For all the focus we've seen on the question of conflicts of interest between Hillary Clinton and both the Clinton Foundation and her and Bill's various sources of income, there's been almost no discussion of what kinds of conflicts of interest Trump's varied business ventures might pose for him if he were to become president. (We should also take a moment to acknowledge how remarkable it is that though Clinton released 15 years of tax returns, Republicans could find nothing in them to criticize. And don't think they didn't look as hard as they could.)

At the moment, we have no idea what Trump's conflicts of interest might be, since his business is privately held. Unlike past presidents who were professional politicians with some investments on the side, Trump has a large and complex business involving lots of partnerships, and he has dismissed the idea of putting his holdings into a blind trust. Instead, he has said he'll allow his children to run the company while he's in the White House, presumably to return it to his day-to-day control once he's done Making America Great Again.

So he'll continue to have a financial interest in his company, which is what makes it particularly important to know what's in Trump's returns. Yet there's no legal requirement for the president to release his or her returns, though every one since Jimmy Carter has done so (if you're so inclined, you can find them all here). Given all the interesting things the returns no doubt contain, and Trump's general lack of concern with adhering to established norms of behavior, it's hard to imagine that he would release them even once he's elected. He's willing to risk his candidacy to keep them secret, so why wouldn't he endure a couple of days of bad press to do the same once he's president?

And no reason looms larger than the possibility, or perhaps probability, that he's not as wealthy as he claims.

It's almost impossible to overstate how sensitive Trump is about the magnitude of his wealth. When one biographer estimated Trump's wealth to be significantly less than he claimed, Trump sued him, seeking $5 billion in damages. When he was roasted by Comedy Central in 2011, he agreed to participate on the condition that comedians could make jokes about his family, his weight, his possible incestuous feelings toward his daughter Ivanka, or his business failures — but they absolutely could not joke about the size of his wealth.

Now maybe it's purely about business: Trump created a persona equating himself with ostentatious displays of wealth, from his plane to his cologne ("Success by Trump") to his apartment, which looks like what you'd get if King Midas projectile vomited all over a New York penthouse. Since his business these days is much less about building things than about licensing his name, it's critical that the public continue to maintain that association.

But it's also hard to avoid the conclusion that it's personal, too. Trump seems either deeply insecure or a rampaging narcissist (or both), and it's obvious that being richer than other people is a large part of how he measures his own value as a human being.

So is he hiding something in those tax returns? Of course he is. Maybe it's something we haven't even thought of, but it's definitely something. If Trump's returns showed him to be engaged in all kinds of profitable businesses, a generous donor to worthy causes, and hugely wealthy, do you think he'd hesitate for an instant before releasing them? But we're never going to find out.