I think he is talking about Modern Monetary Theory, where one of the conclusions they arrive, after studying how modern economies work, is that private sector debt grow when there is not enough government deficit.

https://en.wikipedia.org/wiki/Sectoral_balances

Another of the conclusions is that the national debt, for countries with a floating sovereign currency, is just a number without real meaning.

https://www.nakedcapitalism.com/2014/08/taxation-government-...

Ah. I'm dyslexic and ashamed and I'm going to put myself to bed and try to forget this before the morning comes.

I don't think you are at fault. We abuse acronyms.

Modern monetary theory.