But she is in a new phase, and she reveals herself with few limits: letting the public see her concerns, her fears, her puffy eyes, her extra pounds, her surgical scar and her sense of humor, which is rarely in evidence when she’s in her fist-clenching, turf-defending mode on the tennis court.

“A lot of people see me on the court, and they only judge and see that side of me, and there’s so much more to my life and to me,” she told me. “That’s not me, actually to be honest, on the court. As much a part of my life as it is, I become a different person when I play tennis. The second I step onto the facilities, the grounds, I become a different person, and the second I step off, I’m back to being Serena, no pun intended.

“So I thought it would be interesting, while we were going through this process, if I just took all the curtains away, and I was just myself.”

‘I’m No Different Than Anyone Else’

Williams said she was the one who initiated the process with the HBO series.

“It was super-organic,” she said. “When I found out I was pregnant, I was saying, ‘I really want to get some footage of me,’ because I remember my dad had all this film when we were younger, all this cool footage, and I wanted to start this journey for Olympia, even though she was the size of a raspberry at the time.”

She shared the thought with her agent, Jill Smoller.

“HBO got wind of it, and they said, ‘We would love to do it for you,’ ” Williams said. “My original idea was to do more just Olympia stuff, and then I thought if we’re going to do this, let’s go all out.”