“It’s inconvenient to fall in love at your age, especially when it’s the real thing.”

This would be a great line between a caring mother and a heartbroken daughter, if not for one thing: the “love” between the gifted cellist and her rocker boyfriend doesn’t feel like the real thing.

Based on a novel by Gayle Forman, “If I Stay” tries to equate the drama of teenage romance with the drama of a real life-and-death situation. But even if teen romance can feel like life or death, it often isn’t. And as a result, “If I Stay” feels too shallow to be authentic, especially to anyone old enough to know better.

Chloë Grace Moretz plays Mia, a high school teen in Portland who, as a devotee of classical music, feels like an outcast in a family of diehard rock and rollers. Her father, Denny (Joshua Leonard), used to play drums in a local punk band called Nasty Bruises. Her mother, Kat (Mireille Enos), was the Bruises’ biggest fan. But Mia gravitated toward the cello, and as she nears her high school graduation, a spot at Julliard is in the cards.

One winter afternoon, as Mia is still waiting for a green light from the famous fine arts school, the family (including her younger brother Teddy, played by Jakob Davies) goes out for a drive and gets in a head-on collision with another vehicle. Mia’s injuries leave her in a coma, but thanks to an out-of-body experience, she is able to wander her hospital and observe the different family and friends who come to see her.

As she tries to cope with the reality of her situation, “If I Stay” intercuts flashbacks to fill us in on Mia’s backstory, mostly in terms of her on-again, off-again relationship with Adam (Jamie Blackley), a budding rock star whose own band is just about to hit the big time.

The juxtaposition of these plot lines leads to a fallacy of a quagmire for Mia, who is given the choice between following her family into the unknown or staying behind to pursue her musical dreams and, more particularly, Adam.

The big problem is that Adam isn’t especially thrilled with the idea of Mia attending Julliard 3,000 miles from his efforts to achieve rock and roll superstardom, even though he doesn’t seem to have a problem with leaving Mia for weeks at a time while pursuing his own dreams.

Over the course of the myriad flashbacks, Adam is shown not only to be every bit the dreamboat that a typical starry-eyed teen would fall for but also every bit the naïve, selfish egomaniac you would expect an 18- to 19-year-old aspiring rock guitarist to be. The bizarre result of the film’s binary plot is to leave you feeling like Mia would be better off dying than staying with Adam, though her best option would be to dump Adam and go off to Julliard, where no doubt a much more mature love will come as an adult.

But that wouldn’t quite sell tickets, would it?

The only reason any of this is frustrating is that so much of “If I Stay” is very well done. Moretz does a fine job as Mia, and a scene between her and her grandfather (Stacy Keach) is more touching than anything that happens between Mia and Adam. The musical performances, especially those involving Mia’s cello, are also excellent.

There’s really only one hole in this film (aside from the strange suggestion that there would be tension between a couple of rocker parents and a kid who liked classical music), but that one hole is crippling. Make Adam a bit less of an immature jerk, and “If I Stay” becomes a sweet little movie with a broad appeal.

“If I Stay” is rated PG-13 for language, car-crash related violence, some mild sexuality and underage substance abuse.

Joshua Terry is a freelance writer and photojournalist who appears weekly on "The KJZZ Movie Show" and also teaches English composition for Salt Lake Community College. More of his work is at woundedmosquito.com.