Starting a new decade is always a drag. When I turned the big two-oh last week, I couldn’t help but feel remorse at leaving teenagedom behind.

For a long time I held on to the precocious idea that, before my twenties, I would write my magnum opus or discover my hidden talent for the didgeridoo, perform at Carnegie Hall and become world famous overnight. But forever gone is that window of opportunity to stake my claim at being a child prodigy and, in its place, I’ve been ringing in the new decade with wake-up calls from reality. Please, life, leave a message.

Ironically, one of the calls that I haven’t deferred to voicemail has me realizing how difficult the life of a child prodigy actually is. And, given the present hubbub of movie awards season, it’s only fair to pick on child actors.

Instead of trekking up an incline in their stardom, child actors work to resist the inertia of a downhill career. The roles that put them on the map bank millions, making for records hard to trump and characters hard to erase from collective memory. Even those who defy the trend struggle at times. Case in point (despite the zeitgeist that would beg otherwise): Natalie Portman.

She’s beautiful even when she goes bald and she’s versatile in her acting repertoire, too. Chicken-poxed guisha Queen Amidala scared me shitless as a kid, only to be outdone 11 years later by the spindly feathers that Nina sprouts from her back in “Black Swan.”

But despite Portman’s beauty and the accolades that she’s accrued as one of our generation’s most brilliant star- lets, I still feel underwhelmed and not wholly convinced by her more serious performances. Her expression of permanent constipation in “Black Swan” is a disappointing excuse for acting (and the Best Actress nomination), and those histrionic face contortions may very well be an effort at one-upping the dramatic performances she’s been churning out her entire career.

Since her breakout role in 1994’s “The Professional,” Portman has largely remained in the dramatic film circuit, and, as her recent forays into comedy imply, Nina may be an extension of her very self.

In other words, Portman has a “Black Swan” complex in reverse. Instead of going from the light to dark, she’s leaving dramatic chops behind for light-hearted humor in the just-released rom-com “No Strings Attached” and upcoming medieval stoner flick “Your Highness.”

Although it’s certainly a departure from the norm she established in childhood, comedy agrees with Portman. Her rap on “SNL” in 2006 was ballsy but brilliant in playing off our expectations (“When I was at Harvard / I smoked weed every day / I cheated every test / and snorted all the yay”). In 2009, she effortlessly kept pace with Zach Galifianakis’ awkward character (and his greatest punch line) on his Funny or Die interview series, “Between Two Ferns.”

Portman’s string of comedic movies isn’t the only thing in discord with the straight-laced image she spent her childhood building as a vegan, faithful Jew and Ivy League graduate. Quite to the contrary, she’s soon to enjoy a shotgun wedding, after being knocked up by her choreographer, Benjamin Millipied (yes, you’re supposed to pronounce it with French flair—“MEEL- pee-yeh”—but I’m still thinking of the thousand-legged arthropod).

Her interest in the risque? (now so obvious that no flick of a Hollywood designer’s wand can cover her scarlet “A”) traces back to films as early as 2004’s Academy-Award nominated “Closer,” where Portman played a stripper who told Clive Owen that her lady parts taste like heaven.

What Portman has gone on record saying in the past about gratuitous nudity and sex in film has come back to bite her in the ass. “It’s horrible to be a sex object at any age, but at least when you’re an adult you can make the decision if you want to degrade yourself,” she said a decade ago.

So, either she’s being hypocritical or her Oscar acceptance speech this February will indirectly be an extension of thanks to Aronofsky for the opportunity to “degrade” herself in lesbian sex scenes with Mila Kunis. Or maybe it just wasn’t up to par with her extended nude scene in “Hotel Chevalier” or stripping down to a skimpy bikini in “Your Highness” before the glued eyes of James Franco and Danny McBride.

Those accusations of hypocrisy and selling out are the inevitable price a child actor has to pay for her growing pains. The comparisons made between the current Portman and her inge?nue past may be unfair, since she’s just breaking out of her childhood mold, but that’s what an adolescence spent in the limelight entails.

So, until I get my own big break, here’s to a new decade of screw-ups that won’t go publicly chastised (and hopefully a job when I graduate, too).