Rome title looks like it's just the beginning for rejuvenated Serena

— -- If Serena Williams did hit a motivational wall in the months after losing to Roberta Vinci last September in the final of the US Open, she has not so far been willing to discuss it, let alone cut open a vein and explain herself at length.

You have to infer a lack of motivation from her weekslong absences from the 2016 tour and her long silences. She played only three tournaments this year and lost earlier than usual in two of them, prompting plenty of people to wonder whether this was any way for Williams to prepare for the May 22 start of the French Open and renew her chase of Steffi Graf.

But when will we learn?

Williams needed only six days in Rome last week to remind everyone why she's tennis' queen of the cameo, along with just about everything else.

Who besides Williams can take months off from the tour, then immediately return to staple-gunning down the corners of the court with her groundstrokes and blasting her serve by opponents who couldn't pry even a set off her as she tore to the Italian Open title? Off the court in Rome, Williams finally -- finally -- seemed to be back to her goofy old self, too. She posted a long Snapchat video in which she described in hilarious detail what happened when she sampled the salmon and rice pet meal she ordered at her posh hotel for her dog, Chip.

"Don't judge me ... don't hate on me," Williams comically pleaded into the camera, stifling a laugh but looking piqued.

Opponents long ago got used to the unconventional arc of Williams' career; when will the rest of us quit questioning her? We should never stop being awestruck by her play. But can we finally stop being surprised if, say, she shows up in Paris and mows down the French Open field in the next two weeks, too?

There's a lot of circumstantial evidence to support the idea that Williams -- now in her 20th season on tour -- did indeed hit a wall after her upset loss to Vinci. It was understandable, given the history she was chasing and how insatiably driven she is to win.

But as Williams said to the press last week in Rome, "In my mind, I'm always No. 1, and I think I have always thought that since I have turned pro. And in everyone else's mind, even when I was injured, they are like, 'You're No. 1.' So everyone else thinks it, [too]."

That's true. But it's still different from saying that the stinging end to her 2015 season hasn't stuck with her.

Instead of pulling off the most remarkable feat of her career at the unheard-of age of 33, Williams missed a chance to tie Steffi Graf for the second-most Grand Slam singles titles ever and complete a calendar-year sweep of the majors -- something only Rod Laver, Graf and Margaret Court have done in the Open era. Vinci's win was one of the biggest upsets in tennis history.

Williams immediately took months off, citing exhaustion. When she finally returned in January, she lost a tight final to Angelique Kerber at the Australian Open, disappeared from tour and then lost earlier than usual at Indian Wells and Miami in March.

Then she disappeared for another two months.

Before showing up in Rome, Williams also withdrew from Madrid, citing the flu.

There was "no strategy" behind Williams staying away from the tour so long, Serena's coach, Patrick Mouratoglou, insisted in an email interview last week, explaining "she was sick when it was the moment to travel to play" in Madrid.

But nobody has the flu for three straight months. More was going on with Williams than that.

Just don't expect Serena to explain it until she's ready -- if ever. Her sister Venus, who also played in Rome last week, provided vivid insight into just how cagey Serena can be. Venus surprised reporters as she described how even she only learned about Serena's unannounced star turn in Beyonce's "Lemonade" video album when Serena casually asked her to join her for "something I have to watch on TV tonight at 10" because "I'm in it." It was the same night the album premiered with much fanfare on HBO.

How did Serena pull that off?

"I'm like squeezing water out of a rock," she explained. "If you tell me not to say anything, I'll never speak."

But others do talk about her. And they've ventured to share some thoughts about Serena's state of mind.

Mouratoglou concedes that the mental and physical toll the 2015 season took on Williams was indeed "tough" to deal with because "when you work so hard to achieve something, get so close and finally fail to reach it, the disappointment is big. But she is a champion; she recovered from that. She still can break many records and definitely, she is very motivated to make it happen."

Williams is an avid student of tennis history, even if she doesn't talk about it a lot. She will watch old tapes of Chris Evert-Martina Navratilova, herself and Venus, and many other classic matches, mining the videos for ideas, tips or inspiration. Serena keeps a detailed journal of the matches she plays and her life on tour, too -- something Mouratoglou only found out after she left a notebook in the back of a car one day.

Serena obviously knows that if she'd clinched the calendar-year Grand Slam last year she could've also ended the debate about who is the best women's player of all time, if Graf is even still the frontrunner in that discussion.

But there's also this: While Williams would've found losing the Grand Slam sweep miserable no matter who it came against, losing it to Vinci rather than somebody more her equal had to be an especially rough gut-punch for Serena.

As wonderfully as Vinci played, Serena must've also felt deep down that she lost it. She buckled under the weight of so much history.

She wasn't up to the moment.

And that's a very, very rare pill for Serena to have to swallow.

Williams' irritation, sadness, self-loathing since then -- all emotions she's admittedly struggled with before when she blamed her self-imposed anxiety for how long it took her to tie Evert and Navratilova at 18 slams -- seems to have taken months to go away this time, too.

Those few tournaments Serena did attend earlier this spring now look like false starts. She still wasn't emotionally ready. You could hear that in her gripes about how lesser opponents seem to play "the match of their lives" when they go against her. She sounded world-weary talking about the burden of being No. 1 for so long.

"This will sound ridiculous, but Serena was so gracious when she lost to Angie Kerber [at the Australian Open] and Victoria Azarenka [at Indian Wells] -- and I don't like it when she's gracious," quipped Mary Carillo, who will cover the French Open for the Tennis Channel. "Clearly that one against Vinci took a hell of a lot out of her. What I hope for is that she uses it as fuel and doesn't let it burn her up. Take it the other way."

Mouratoglou now suggests that's exactly what's happening heading into the French Open.

"I do not think that she lost her motivation at all," Mouratoglou wrote. "If people would see her practice, they would probably change their mind."

Evert, who played until she was 34, the same age Serena is now, believes Williams is wise to trim back her schedule this year since this summer will bring, in rapid succession, the French Open, Wimbledon, the Rio Summer Olympics and the US Open.

"I think she hasn't shown anything, the hunger or that spark we're used to seeing," Evert said just before Williams won in Rome. "I think in the bigger picture, she wasn't going to burn herself out. I don't think it's a bad idea. You can't peak for four months in a row, especially when you're 34."

Navratilova, speaking on a WTA podcast a few weeks ago, agreed there was no need to "panic" about where Williams' mind or game was earlier this year. Nor does Navratilova believe -- as some have speculated -- that Williams' long hiatus was the beginning of the end.

"It just seems to me that she's not happy on the court," Navratilova said. "If she finds that emotion -- I won't say joy, but you know, passion for being in those fights -- I think she'll right the ship. There's nothing wrong with her game."

Despite the sabbatical Williams just ended, all five experts contacted for this story -- Evert, Navratilova, Carillo, Paul Annacone and Justin Gimelstob -- believe Williams will win more majors before she quits.

"Yes," Gimelstob, a Tennis Channel analyst, emphatically said, breaking into a laugh that suggested even posing the question was silly.

How about multiple majors?

"Yes, yes," Gimelstob shot back.

Annacone, who coached Pete Sampras and Roger Federer later in their careers, agreed, saying, "I'll be absolutely shocked if she doesn't."

Mouratoglou insists Williams is taking a business-as-usual approach to the rest of 2016. Asked what their goals are for their now-shortened year, Mouratoglou wrote back: "We set the standards high, because she can achieve much higher goals than anyone.

"We obviously have the goal to win Roland Garros, Wimbledon, the US Open and the Gold Medal at the Olympics."

In other words, Serena wants it all.

Same as she ever has.

ESPN.com's Greg Garber contributed to this report.