PHOTO: I wear $10 wristwatch – Bill Gates

And this summer, for his wife’s 50th birthday, Bill Gates and family headed to Austria for a “Sound of Music” vacation. Where he sang and, he admitted, wore Lederhosen.

Such true confessions came Monday morning at POLITICO’s Lessons From Leaders inaugural event, which hosted Gates as the featured guest.

Chief White House correspondent Mike Allen solicited the timepiece tidbit as Gates talked about the new technologies that allow people to monitor their own health. But the other intel was revealed at the end of nearly an hour of conversation.

Gates, with a net worth that Forbes on Monday estimated at $81 billion, gamely went along with the fun-facts questions.

A couple other details: He plays a lot of tennis and recommends “a full body swing” for the best game. He reads The Economist cover to cover weekly and is finishing a new book by Henry Kissinger titled “World Order.”

But the most enjoyable read he’s had lately is “The Rosie Project,” which he picked up because wife Melinda was laughing out loud over it.

According to the book’s online synopsis, it’s about “a brilliant yet socially inept professor of genetics, who’s decided it’s time he found a wife” and approaches this goal with a “a sixteen-page, scientifically valid survey to filter out the drinkers, the smokers, the late-arrivers.”