Bill Gates speaks to reporters at Trump Tower on Dec. 13, 2016 in New York City. (Drew Angerer/Getty Images)

Bill Gates recounted his bizarre encounters with President Trump, who commented on his daughter's appearance and reportedly asked about the difference between HIV and HPV.

MSNBC's "All In With Chris Hayes" aired video footage on Thursday that showed the Microsoft founder talking about meeting Trump for the first time in December 2016 before he visited the White House four months later.

President Trump speaks during a meeting with NATO Secretary General Jens Stoltenberg in the Oval Office of the White House in Washington, D.C. on May 17, 2018. (SAUL LOEB/AFP/Getty Images)

While the Human Immunodeficiency Virus and the Human Papillomavirus can be sexually transmitted, the two are very different.

HIV weakens a person's immune system and can lead to AIDS, while HPV is a virus with multiple strains that can lead to genital warts or cervical cancer.

Gates said he once avoided Trump at an event, and didn't meet the real estate tycoon until December 2016.

Trump, who already knew Gates' daughter Jennifer Gates, apparently had a lot to say about the way she looked.

"Anyway, so when I first talked to him, it was actually kind of scary how much he knew about my daughter's appearance. But Linda didn't like that too well," Gates said, referencing his wife Melinda Gates.

When the two met again four months later, Gates said the President was thinking about setting up a commission to look into the downsides of vaccines.

"And I said no, that's a dead end. That would be a bad thing. Don't do that," Gates said, before recounting the President's questions about HPV and HIV.

The President also reportedly referred to himself in the third person, and told him, "Trump hears you don't like what Trump is doing."