I suspect that the big problem (for me) was the lack of momentum. This is a tough problem to fix when transmuting a personal memoir into a film, since real life is rarely helpful enough to follow the "rising action - climax - falling action" model that works so well in filmmaking.
It also used the risky trick of relying heavilly on period music to convey how the viewer is meant to feel at given points. Personally I don't hate this trick, but I'm not sure they pulled it off as well as they could have. Still, they made some fine selections, and I was quite happy to be reminded what a marvelous song Al Stewart's "Year of the Cat" is. I probably hadn't heard that song in twenty years.