The film, which is inspired by Mills' real life, flashes back and forth between Oliver's childhood memories, the last few years of his father's life, and the present day, where Oliver struggles with the sometimes funny, sometimes sad messiness of love, loss and new beginnings.
"Mike never expected me to do an impersonation of him, but I wanted to portray him and what he is about accurately," he says. "I had him record all the dialogue so I could listen to it before each scene and have a flavor of his voice. I watched him a lot. I tried to feel like him as I moved through the scenes."
Building the father/son bond quickly turned from an acting exercise into an adventure in modern fashion. The first day McGregor and Plummer met, Mills sent them shopping at Barney's. "Christopher became obsessed with buying black skinny jeans," says McGregor. "He tried on I don't know how many pairs! I put about $1200.00 of skinny jeans on my credit card!"
One of the most intriguing parts of the story for McGregor was Oliver's journey to understand his parents' lives -- and their influence on his ability to fall in love. "The idea that the relationship that you are first party to is your parents' relationship -- and how that affects your ability to go on and have successful relationships or not -- is fascinating," he says.
Guiding Oliver in the ways of love is Arthur, the Jack Russell Terrier he inherits from Hal. Oliver has conversations with Arthur, who responds via very articulate subtitles. So perhaps it's not totally surprising that the day the film wrapped, McGregor adopted a poodle-mix named Sid. "I realized that I was missing having a dog. I'm still knocking about with a little white dog on a lead," he says.
Meanwhile, after working so closely with Mills, McGregor is considering directing -- but not for the reason you might think. "Mainly I'd like to direct so I can turn up to work not have to take off my clothes" he says. "Every day I turn up to work I've got to take my clothes off and put on someone else's clothes. It would be quite nice to turn up to work and just wear my own clothes all day."