Donald Trump has a talking point that he believes overshadows his embarrassing failures: economic growth, as measured by the Gross Domestic Product, is still pretty good.

Two weeks ago, for example, after GDP for the second quarter was revised up to 3.1%, the president boasted via Twitter, “Many people thought it would be years before that happened.” No one actually thought that – because 3.1% quarterly growth has been quite common since the end of the Great Recession.

But Trump keeps pretending otherwise, either because he’s economically illiterate or because he enjoys pretending to be economically illiterate. During his interview with Mike Huckabee over the weekend, for example, the president added in reference to the latest GDP data, “Everybody was shocked. They said it wouldn’t happen for years.”

Again, nobody was shocked, just as nobody said it’d take years to see quarterly growth that’s been routine for quite a while.

In a new interview with Forbes, Trump went just a little further.

He’s similarly proud of the GDP. “So GDP last quarter was 3.1%. Most of the folks that are in your business, and elsewhere, were saying that would not be hit for a long time. You know, Obama never hit the number.”

Maybe a chart will help drive the point home. I put this image together to show the GDP by quarter since the start of the Great Recession nearly a decade ago:

According to Trump, under Barack Obama’s presidency, the economy never reached quarterly growth of 3.1%. And that’s true, just so long as we overlook what happened in 2009, 2010, 2011, 2013, 2014, and 2015. To the extent that reality has any meaning in the debate, in the Obama era, quarterly growth reached or exceeded 3.1% eight times in eight years.

So when Trump says Obama “never hit the number,” it’s the exact opposite of the truth.

When the Forbes interviewer reminded the president of how wrong he is, Trump replied Obama never reached 3.1% “on a yearly basis.” And while that actually is true, Trump hasn’t reached that number on a yearly basis, either.

Because he’s so confused about the basics of this issue, the president recently boasted that his tax cuts could push GDP growth to 6%. That, of course, is hopelessly bonkers, and according to the Federal Reserve, the Congressional Budget Office, and his own administration, Trump will be lucky to see growth half that strong.

Whether Trump will ever understand any of this is unclear, but I recommend keeping expectations low.