The world’s second richest man, Bill Gates, hums the Bruno Mars song “I wanna be a billionaire so freakin bad” to himself and knows some Lady Gaga songs.

That’s according to the recent interview with UK’s Daily Mail, in which the Microsoft founder talked about family, fortune, wealth and more. The billionaire philanthropist talked on a personal level on Saturday, two days before the Global Alliance for Vaccines and Immunisation (GAVI) conference that took place in London on Monday, when Britain and Gates pledged $2.3 billion to fund vaccination programs to protect children in poor countries against diseases like diarrhoea and pneumonia.

Below are the 5 facts Gates revealed during the interview.

Fact #1 Gates’ kids tease him with “Billionaire” song

“The Billionaire song is what my kids tease me with,” he told Daily Mail. “They sing it to me. It’s funny,” he said. “The 12-year-old is always worried about the nine-year-old listening to songs with bad words. So he’s like, ‘No! Skip that one!’ So I only know some Lady Gaga songs,” Gates revealed.

Fact # 2 Gates’ children will inherit a ‘minuscule portion’ of his wealth

“I don’t think that amount of money would be good for them. They have to find their own way. They will be given an unbelievable education and that will all be paid for. And certainly anything related to health issues we will take care of. But in terms of their income, they will have to pick a job they like and go to work,” Gates said.

Fact # 3 Gates prefers his foundation work to working at Microsoft

“If people look and see that childhood deaths dropped from nine million a year to four million because of our investment, then wow! I liken what I’m doing now to my old job. I worked with a lot of smart people; some things went well, some didn’t go so well. But when you see how what we did ended up empowering people, it’s a very cool thing,” said Bill Gates, who retired from Microsoft in 2008.

Fact # 4 Legacy is a ‘stupid’ thing for Gates

That’s what he said during the interview. “I don’t want a legacy,” he said. He would rather rescue the Codex Leicester, one of Leonardo da Vinci’s notebooks he bought in 1994 for $30.8 million, from his home in a fire. “I have documents by Isaac Newton and Abraham Lincoln. I have some pretty nice art too. It would be a shame to lose any of that,” he added.

Fact # 5 People in third world nation don’t know Gates

“They don’t know who I am, because it doesn’t relate to their world. If you’re a person struggling to eat and stay healthy you might have heard about Michael Jordan or Muhammad Ali, but you’ll never have heard of Bill Gates,” he said referring to his visit to India earlier this year.