The course of true love never did run smooth and it follows an infuriatingly long-winded route in Love, Rosie.

Based on Cecelia Ahern's 2004 novel Where Rainbows End, Christian Ditter's exasperating comedy of errors concerns two attractive, intelligent and good-humoured best friends, who waste some of the best years of their lives ignoring how ideally suited they are.

Instead, the perfectly aligned protagonists pursue unfulfilling relationships with other people or embrace solitude rather than taking a tiny leap of faith from friendship to something deeper.

The film is built on traditional romcom foundations, flinging obstacles in the path of the best friends to explain why we have to sit through 12 years of their dithering before the inevitable moment of surrender.

Juliette Towhidi's script surfs a wave of silliness and falls over in pivotal scenes including an argument, which culminates with the eponymous heroine caterwauling, "Can you stop the psychobabble and can we talk like English people?"

On this evidence, no they can't.

Rosie Dunne (Lily Collins) and Alex Stewart (Sam Claflin) live across the road from each other and have been best friends since they were five years old.

On her 18th birthday, a delirious and drunken Rosie shares a smoldering kiss with Alex but forgets about the smooch thanks to a bump to the head.

He doesn't forget and jokingly skirts the issue of romance, which Rosie shoots down by quipping, "You will forever by the guy who wiped bogies on my party dress."

Their unseemingly unbreakable bond shatters when Alex moves to Boston to attend university, leaving behind Rosie with her parents Dennis (Lorcan Cranitch) and Alice (Ger Ryan) in Dublin.

The pals follow divergent paths.

Rosie turns to sassy best friend Ruby (Jaime Winstone) to buoy her spirits and an old school crush called Greg (Christian Cooke) with impressive abs provides a passable substitute for Alex.

Meanwhile, Alex succumbs to the aggressive overtures of supermodel Bethany Williams (Suki Waterhouse) and social climber Sally (Tamsin Egerton).

Love, Rosie will test the patience of the most hopeless romantic.

Collins and Claflin age over the course of the film from nervous 18-years-olds to jaded thirty-somethings simply by changing their hairstyles.

Our incredulity reaches its peak when a resplendent 25-year-old Collins stands next to talented 13-year-old actress Lily Laight and we're asked to believe they are single mother and daughter.

Of the supporting cast, only Winstone registers, having a ball as a straight-talking confidante, whose dyed hair is as colourful as her language.

If it was possible to develop a 5D cinema experience and allow audiences to physically reach into the screen and slap characters, I would have battered and bruised the two leads senseless within the opening 15 minutes.