What goes up, must come down — and perhaps nowhere is this adage more accurate than in Tinseltown.
While it's certainly no secret that Justin Bieber has encountered something of a rough patch, only time will tell whether the teen mogul will manage to reclaim his former glory… or hit rock bottom.
In the meantime, however, Hollywood A-listers are chiming in with their two cents for this multimillionaire. The latest star to offer up some thoughts is new father Channing Tatum, who spoke candidly about his concern for the Biebs.
"I worry about Bieber, man," he revealed in the latest issue of Vanity Fair. "That kid’s wildly talented. I hope he doesn’t fall down into the usual ways of young kids because it’s so hard for someone to be responsible when they’re not asked to be."
And in case there was any question, Tatum includes himself in that group. "We’re not asked to do things ourselves. You have someone there with a coffee. ‘You want food? I’ll get you food.’ I put my bag in the trunk yesterday — I can’t drive here — so my driver, great guy, Terry, amazing, I call him T-Bone, I drop my bag in and left the trunk open. And I get around to my door, and I’m like, 'What the f--- am I doing? That’s not my behavior.'"
While the "White House Down" star seems to have his diva behavior in check, Bieber might not. Back in March, the pop star showed up a whopping two hours late for his own concert, and got a (verbal) lashing from rock legend Jon Bon Jovi as a result.
[Related: Justin Bieber's Terrible 2013]
"Do it once, you can be forgiven ... Do it enough times and shame on you. They won't have your back. Then it just becomes a cliché. It's really not cool — you're an a--hole."
But there are stars who've got Bieber's back, like his fellow Canadians, The Barenaked Ladies.
“I don’t think that any of us can relate to the level of fame and catapult to stardom that he’s experiencing,” the group's Ed Robertson told Yahoo! Music in an interview Wednesday. “If I could give him any advice, I would just say to keep it together because he has so much f---ing talent. It would be a shame. He is an insanely talented young man. I challenge anyone to keep their s--- together while touring all over the world.”
“Take some time off,” band member Tyler Stewart added. “Take a year off and go find a place where you can work on your music because it’s good. I think he’s really got it in him to be a career artist because he’s an amazing entertainer; he just has to not burn out.”
Will Smith also recently came to Justin's defense, tweeting of his son Jaden's friend, "There are things that are just simple and normal for a 19-year-old to do, just when I was 19 there was no Twitter, the things that I was doing — I was able to have privacy because everybody's phone didn't have a camera on it."
[Related: Justin Bieber Music Videos]
Not so fast, says Keyshawn Johnson. After an incident in which Johnson reported Bieber to authorities for driving through their Calabasas neighborhood at dangerous speeds, the former NFL star spoke out against the lead-footed teen.
"You got a 19-year-old kid… feeling entitled… speeding up and down the highway… that's why all the neighbors is mad," he explained. "You can't do that."
Drake Bell isn't a fan either. The "Drake and Josh" star ragged on Bieber, tweeting, "Justin Bieber is 5'6" now I understand why you guys love him!! He's the same as all you 12 year olds! I totally get it now sorry guys."
And when Bieber was left off the list of Grammy nominees, fellow musician Patrick Carney, drummer for The Black Keys, added insult to injury.
Asked whether the singer deserved a nomination from the Recording Academy, Carney quipped, "The Grammys are … for music and not for money. And he's making a lot of money. He should be happy, I guess."
He seems happy enough, most of the time. He seemed to have a good time at the Anne Frank House, at least. After he left a somewhat mystifying message in the museum guest book expressing that he'd hope Frank "would have been a Belieber," funny man Ricky Gervais took to Twitter to express his "support."
"I agree with Jusin Bieber," he tweeted. "Anne Frank would've loved his stuff. It's perfect for being played really really quietly so no one can hear it."
Usher (who discovered Bieber), however, doesn't agree with Gervais. The music mogul recently explained his take on things.
"He's a teenager having to live his life in front of a camera. Imagine if you had to do that as a teenager."
[Related: Justin Bieber's 19 Most Ridiculous Looks]
Usher may have a point, but so does Olivia Wilde, who recently tweeted, "Bieber, put your f---ing shirt on."
If you're going to live in front of the camera — no matter who you are — that's probably a good idea.
More Celebrity Features on Yahoo!: