AUSTIN (KXAN) — Just after 3 a.m. Monday, Tesla founder Elon Musk said he has COVID-19 for the second time.

The billionaire who owns both the electric car manufacturer headquartered in Austin, and space exploration company SpaceX, tweeted the news early Monday, saying, “Covid-19 is the virus of Theseus.”

“How many gene changes before it’s not Covid-19 anymore?” he continued. “I supposedly have it again, but almost no symptoms.”

The reference to the Greek mythological hero seems to be about the ship of Theseus, which in philosophy wrestles with a paradox: If an object has all the parts that comprise it replaced, is it still the same thing after the changes?

Musk, who has 79.4 million Twitter followers and tweets at all hours, caused a stir on the social media platform the first time he tested positive for the virus. He drew the ire of a Canadian doctor who referred to him as “Space Karen” after complaining about conflicting test results in November 2020.

“Something extremely bogus is going on,” Musk said after multiple antigen tests came back both positive and negative. Emma Bell, Ph.D, a postdoc of bioinformatics at a Toronto hospital, unleashed an aggressive explanation as to why that could happen, and her name-calling sparked a meme that entertained internet users for weeks.

Earlier in March on Twitter, Musk tried to pick a fight with Russian president Vladimir Putin over the invasion of Ukraine, and he used Starlink satellites to restore internet service to Ukraine residents as combat from the war knocked out service.