A pretty man falls for an old flame in 'Age of Adaline'

Arrested development is having a moment on TV and in the movies. So it's a little shocking to watch "The Age of Adaline," which features a 20-something acting like a grown-up. The title character doesn't flash her privates in public or get blackout drunk or sleep around. She's mature. She reads for pleasure, sips champagne in moderation and spends quiet evenings with her King Charles Spaniel.

She's a centenarian trapped in a 29-year-old's body, and not figuratively speaking. She's actually 106 years old.

Blake Lively plays Adaline Bowman, a woman of many secret identities and hairstyles, who was rendered ageless sometime around Prohibition after a fluke involving both hypothermia and a lightning strike. In the year 2014, she goes by the name Jenny and pretends that her daughter, Flemming (Ellen Burstyn), is her grandmother. FBI agents once detained her with the encouraging promise that she had nothing to worry about; they just wanted to run some tests. Ever since, Adaline has been on the lam, changing her identity and town every decade to avoid becoming a lab rat or sideshow attraction.

Therefore, she can never form a lasting relationship outside of her daughter and her dog. But then she meets Ellis (Michiel Huisman), who must be her soul mate if for no other reason than he is almost as excessively gorgeous as she is. So begins a fairy-tale romance that can be delightfully preposterous but also ludicrously flimsy.

For starters: Who is Adaline? We never get a sense of her beyond her many accomplishments. She can read Braille and speak Portuguese; she could probably beat Ken Jennings at Trivial Pursuit. And yet, she's inscrutable. Lively creates the loveliest shell imaginable, of course, but her sedate demeanor and wooden delivery make her seem like a robot. And kudos to her for trying to affect a retro cadence, but if her octogenarian daughter speaks like it's 2014, why can't she?

Luckily, Ellis supplies enough energy to make up for Adaline's personality deficiency. He's quirky and earnest, sending Adaline a "bouquet" of books, including "White Oleander" and "Daisy Miller." And never has a guy been so blatantly vulnerable about his lovey-dovey feelings. Their pas de deux turns out to be occasionally thrilling and quite romantic, but the story flies off the rails when he takes her to meet his parents. His astronomer father, William (Harrison Ford in eye-magnifying glasses), used to know Adaline. In fact, the two were "very close," he says multiple times.

But does this mean what we think it means? "The Age of Adaline" won't get into the salacious details of the 1960s-era relationship because the idea of a woman sleeping with two generations of men in the same family is icky.

Rather than spend time going down that rabbit hole, the movie distracts us by answering less interesting questions no one asked. For example, how did Adaline manage to provide for herself after all these years? She was an early investor in Xerox, of course. And then there's the scientific basis for Adaline's condition, which is relayed occasionally by an overbearing narrator who provides more unintentional comedy than insight. He uses a lot of big, arcane words that might have been pulled off of the periodic table of elements, for all this unscientific viewer knows, as if anyone watching actually thought the plot was plausible. The melodrama has all the science of "18 Again!"

"The Age of Adaline" works best as a simple story of boy meets girl; girl falls in love; girl mulls whether or not to reveal that she'll stay young forever. Everything else is just a lot of unnecessary noise.